Application of patient-derived tumor models in anticancer drug development and individualized medicine

Malignant tumor is the second leading cause of death due to its high incidence, lack of effective treatment and poor prognosis. The evaluation of anticancer drugs used to based on NCI-60 cell line models, but the limited heterogeneity and the divorce from clinical practice of models lead to extremely low success rate of novel anticancer drugs during clinical trials (less than 10%). In recent years, because of the high heterogeneity and human derived tumor matrix, patient-derived tumor models have been gradually applied to the preclinical evaluation of various antitumor drugs, which shows certain advantages in predicting the clinical efficacy of antitumor drugs. Optimize the drug combination through patient-derived tumor models to achieve individualized medicine has gradually become an indispensable strategy in clinical cancer therapy. The current review summarized the development of patient-derived tumor models, characterized the application, advantages and challenges of them in preclinical antitumor drug evaluation and clinical precise medicine, which will provide a scientific basis and novel insights for further basic research, drug development and clinical application.

Patient-derived xenograft model in colorectal cancer basic and translational research

Colorectal cancer(CRC)is one of the most popular malignancies globally,with 930000 deaths in 2020.The evaluation of CRC-related pathogenesis and the discovery of po-tential therapeutic targets will be meaningful and helpful for improving CRC treat-ment.With huge efforts made in past decades,the systematic treatment regimens have been applied to improve the prognosis of CRC patients.However,the sensitivity of CRC to chemotherapy and targeted therapy is different from person to person,which is an important cause of treatment failure.The emergence of patient-derived xenograft(PDX)models shows great potential to alleviate the straits.PDX models possess similar genetic and pathological characteristics as the features of primary tu-mors.Moreover,PDX has the ability to mimic the tumor microenvironment of the original tumor.Thus,the PDX model is an important tool to screen precise drugs for individualized treatment,seek predictive biomarkers for prognosis supervision,and evaluate the unknown mechanism in basic research.This paper reviews the recent advances in constructed methods and applications of the CRC PDX model,aiming to provide new knowledge for CRC basic research and therapeutics.

Patient-derived non-small cell lung cancer xenograft mirrors complex tumor heterogeneity

Objective:Patient-derived xenograft(PDX)models have shown great promise in preclinical and translational applications,but their consistency with primary tumors in phenotypic,genetic,and pharmacodynamic heterogeneity has not been well-studied.This study aimed to establish a PDX repository for non-small cell lung cancer(NSCLC)and to further elucidate whether it could preserve the heterogeneity within and between tumors in patients.Methods:A total of 75 surgically resected NSCLC specimens were implanted into immunodeficient NOD/SCID mice.Based on the successful establishment of the NSCLC PDX model,we compared the expressions of vimentin,Ki67,EGFR,and PD-L1 proteins between cancer tissues and PDX models using hematoxylin and eosin staining and immunohistochemical staining.In addition,we detected whole gene expression profiling between primary tumors and PDX generations.We also performed whole exome sequencing(WES)analysis in 17 first generation xenografts to further assess whether PDXs retained the patient heterogeneities.Finally,paclitaxel,cisplatin,doxorubicin,atezolizumab,afatininb,and AZD4547 were used to evaluate the responses of PDX models to the standard-of-care agents.Results:A large collection of serially transplantable PDX models for NSCLC were successfully developed.The histology and pathological immunohistochemistry of PDX xenografts were consistent with the patients’tumor samples.WES and RNA-seq further confirmed that PDX accurately replicated the molecular heterogeneities of primary tumors.Similar to clinical patients,PDX models responded differentially to the standard-of-care treatment,including chemo-,targeted-and immuno-therapeutics.Conclusions:Our established PDX models of NSCLC faithfully reproduced the molecular,histopathological,and therapeutic characteristics,as well as the corresponding tumor heterogeneities,which provides a clinically relevant platform for drug screening,biomarker discovery,and translational research.

Translational pancreatic cancer research:a comparative study on patient-derived xenograft models

AIM To assess the viability of orthotopic and heterotopic patient-derived pancreatic cancer xenografts implanted into nude mice.METHODS This study presents a prospective experimental analytical follow-up of the development of tumours in mice upon implantation of human pancreatic adenocarcinoma samples. Specimens were obtained surgically from patients with a pathological diagnosis of pancreatic adenocarcinoma. Tumour samples from pancreatic cancer patients were transplanted into nude mice in three different locations(intraperitoneal, subcutaneous and pancreatic). Histological analysis(haematoxylin-eosin and Masson's trichrome staining) and immunohistochemical assessment of apoptosis(TUNEL), proliferation(Ki-67), angiogenesis(CD31) and fibrogenesis(α-SMA) were performed. When a tumour xenograft reached the target size, it was reimplanted in a new nude mouse. Three sequential tumour xenograft generations were generated(F1, F2 and F3).RESULTS The overall tumour engraftment rate was 61.1%. The subcutaneous model was most effective in terms of tissue growth(69.9%), followed by intraperitoneal(57.6%) and pancreatic(55%) models. Tumour development was faster in the subcutaneous model(17.7 ± 2.6 wk) compared with the pancreatic(23.1 ± 2.3 wk) and intraperitoneal(25.0 ± 2.7 wk) models(P = 0.064). There was a progressive increase in the tumour engraftment rate over successive generations for all three models(F1 28.1% vs F2 71.4% vs F3 80.9%, P < 0.001). There were no significant differences in tumour xenograft differentiation and cell proliferation between human samples and the three experimental models among the sequential generations of tumour xenografts. However, a progressive decrease in fibrosis, fibrogenesis, tumour vascularisation and apoptosis was observed in the three experimental models compared with the human samples. All three pancreatic patient-derived xenograft models presented similar histological and immunohistochemical characteristics.CONCLUSION In our experience, the faster development andgreatest number of viable xenografts could make the subcutaneous model the best option for experimentation in pancreatic cancer.

Spontaneous xenogeneic GvHD in Wilms'tumor Patient-Derived xenograft models and potential solutions

Severely immunocompromised NOD.Cg-PrkdcIl2rg(NOG)mice are among the ideal animal recipients for generation of human cancer models.Transplantation of human solid tumors having abundant tumor-i nfiltrating lymphocytes(TILs)can induce xenogeneic graft-versus-host disease(xGvHD)following engraftment and expansion of the TILs inside the animal body.Wilms’tumor(WT)has not been recognized as a lymphocyte-predominant tumor.However,3 consecutive generations of NOG mice bearing WT patient-derived xenografts(PDX)xenotransplanted from a single donor showed different degrees of inflammatory symptoms after transplantation before any therapeutic intervention.In the initial generation,dermatitis,auto-amputation of digits,weight loss,lymphadenopathy,hepatitis,and interstitial pneumonitis were observed.Despite antibiotic treatment,no response was noticed,and thus the animals were prematurely euthanized(day 47 posttransplantation).Laboratory and histopathologic evaluations revealed lymphoid infiltrates positively immunostained with anti-human CD3 and CD8 antibodies in the xenografts and primary tumor,whereas no microbial infection or lymphoproliferative disorder was found.Mice of the next generation that lived longer(91 days)developed sclerotic skin changes and more severe pneumonitis.Cutaneous symptoms were milder in the last generation.The xenografts of the last 2 generations also contained TILs,and lacked lymphoproliferative transformation.The systemic immunoinflammatory syndrome in the absence of microbial infection and posttransplant lymphoproliferative disorder was suggestive of xGvHD.While there are few reports of xGvHD in severely immunodeficient mice xenotransplanted from lymphodominant tumor xenografts,this report for the first time documented serial xGvHD in consecutive passages of WT PDX-bearing models and discussed potential solutions to prevent such an undesired complication.

Specific bone region localization of osteolytic versus osteoblastic lesions in a patient-derived xenograft model of bone metastatic prostate cancer

Objective:Bone metastasis occurs in up to 90%of men with advanced prostate cancer and leads to fractures,severe pain and therapy-resistance.Bone metastases induce a spectrum of types of bone lesions which can respond differently to therapy even within individual prostate cancer patients.Thus,the special environment of the bone makes the disease more complicated and incurable.A model in which bone lesions are reproducibly induced that mirrors the complexity seen in patients would be invaluable for pre-clinical testing of novel treatments.The microstructural changes in the femurs of mice implanted with PCSD1,a new patient-derived xenograft from a surgical prostate cancer bone metastasis specimen,were determined.Methods:Quantitative micro-computed tomography(micro-CT)and histological analyses were performed to evaluate the effects of direct injection of PCSD1 cells or media alone(Control)into the right femurs of Rag2
/
gc
/
male mice.Results:Bone lesions formed only in femurs of mice injected with PCSD1 cells.Bone volume(BV)was significantly decreased at the proximal and distal ends of the femurs(p<0.01)whereas BV(p<0.05)and bone shaft diameter(p<0.01)were significantly increased along the femur shaft.Conclusion:PCSD1 cells reproducibly induced bone loss leading to osteolytic lesions at the ends of the femur,and,in contrast,induced aberrant bone formation leading to osteoblastic lesions along the femur shaft.Therefore,the interaction of PCSD1 cells with different bone region-specific microenvironments specified the type of bone lesion.Our approach can be used to determine if different bone regions support more therapy resistant tumor growth,thus,requiring novel treatments.

Molecular phenotypes reveal heterogeneous engraftments of patient-derived hepatocellular carcinoma xenografts

Objective:Patient-derived xenograft(PDX)models provide a promising preclinical platform for hepatocellular carcinoma(HCC).However,the molecular features associated with successful engraftment of PDX models have not been revealed.Methods:HCC tumor samples from 76 patients were implanted in immunodeficient mice.The molecular expression was evaluated by immunohistochemistry.Patient and tumor characteristics as well as tumor molecular expressions were compared for PDX engraftment using the Chi-square test.The independent prediction parameters were identified by logistic regression analyses.Results:The engraftment rate for PDX models from patients with HCC was 39.47%(30/76).Tumors from younger patients and patients with elevated preoperative alpha-fetoprotein level had higher engraftment rates.Tumors with poor differentiation and vascular invasion were related to engraftment success.The positive expression of CK19,CD133,glypican-3(GPC3),and Ki67 in tumor samples was associated with engraftment success.Logistic regression analyses indicated that GPC3 and Ki67 were two of the strongest predictors of PDX engraftment.Tumors with GPC3/Ki67 phenotypes showed heterogeneous engraftment rates,with 71.9%in GPC3^(+)/Ki67^(+)tumors,30.8%in GPC3^(-)/Ki67^(+)tumors,15.0%in GPC3^(+)/Ki67^(-)tumors,and 0 in GPC3^(-)/Ki67^(-)tumors.Conclusions:Successful engraftment of HCC PDXs was significantly related to molecular features.Tumors with the GPC3+/Ki67+phenotype were the most likely to successfully establish HCC PDXs.

Advantages and limitations in the establishment and utilization of patient-derived xenografts in gastric cancer

Owing to the high genetic heterogeneity of tumors, small number of therapeutic strategies available, and frequent presentation of drug resistance, the prognosis for patients with advanced gastric cancer(AGC) are unsatisfactory. The utility of traditional cancer cell lines in translational research is limited by their poor correspondence to the genomic alterations and expression profiles that occur in actual patient tumors. In the last decade, increasing attention has been given to patient-derived tumor xenografts(PDTXs), which can faithfully recapitulate the histopathology, molecular characteristics, and therapeutic responses of the patient's tumor. However, the widespread development and utilization of PDTXs is restricted by factors such as the timeframe of establishment, lymphoma transformation during passaging, the immunodeficient microenvironment, and pharmacokinetic differences between mice and humans. In this review, we summarize the establishment and characterization of PDTX models for gastric cancer(GC). We then weigh the advantages and limitations of PDTXs when used to evaluate novel compounds, identify effective biomarkers, demonstrate resistance mechanisms, and predict clinical outcomes.

Patient-derived organoids (PDOs) and PDO-derived xenografts (PDOXs): New opportunities in establishing faithful pre-clinical cancer models

One of the major bottlenecks in advancing basic cancer research and developing novel cancer therapies is the lack of in vitro pre-clinical models that faithfully recapitulate tumor properties in the patients.Monolayer cultures of cancer cell lines usually lose the heterogeneity of the parental tumors,while patient-derived xenograft(PDX)suffers from its time-and resource-intensive nature.The emergence of organoid culture system and its application in cancer research provides a unique opportunity to develop novel in vitro cancer pre-clinical models.Here we review the recent advances in utilizing organoids culture system and other related three-dimensional culture systems in studying cancer biology,performing drug screening,and developing cancer therapies.In particular,we discuss the advantages of applying xenograft initiated from patient-derived organoids(PDOs)as a faithful cancer pre-clinical model in basic cancer research and precision medicine.

The evolution of cancer genomic medicine in Japan and the role of the National Cancer Center Japan

The journey to implement cancer genomic medicine(CGM)in oncology practice began in the 1980s,which is considered the dawn of genetic and genomic cancer research.At the time,a variety of activating oncogenic alterations and their functional significance were unveiled in cancer cells,which led to the development of molecular targeted therapies in the 2000s and beyond.Although CGM is still a relatively new discipline and it is difficult to predict to what extent CGM will benefit the diverse pool of cancer patients,the National Cancer Center(NCC)of Japan has already contributed considerably to CGM advancement for the conquest of cancer.Looking back at these past achievements of the NCC,we predict that the future of CGM will involve the following:1)A biobank of paired cancerous and non-cancerous tissues and cells from various cancer types and stages will be developed.The quantity and quality of these samples will be compatible with omics analyses.All biobank samples will be linked to longitudinal clinical information.2)New technologies,such as whole-genome sequencing and artificial intelligence,will be introduced and new bioresources for functional and pharmacologic analyses(e.g.,a patient-derived xenograft library)will be systematically deployed.3)Fast and bidirectional translational research(bench-to-bedside and bedside-to-bench)performed by basic researchers and clinical investigators,preferably working alongside each other at the same institution,will be implemented;4)Close collaborations between academia,industry,regulatory bodies,and funding agencies will be established.5)There will be an investment in the other branch of CGM,personalized preventive medicine,based on the individual's genetic predisposition to cancer.

Reduction-responsive nucleic acid nanocarrier-mediated miR-22 inhibition of PI3K/AKT pathway for the treatment of patient-derived tumor xenograft osteosarcoma

miRNAs are important regulators of gene expression and play key roles in the development of cancer, including osteosarcoma. During the development of osteosarcoma, the expression of miR-22 is significantly downregulated, making miR-22 as a promising therapeutic target against osteosarcoma. To design and fabricate efficient delivery carriers of miR-22 into osteosarcoma cells, a hydroxyl-rich reduction-responsive cationic polymeric nanoparticle, TGIC-CA (TC), was developed in this work, which also enhanced the therapeutic effects of Volasertib on osteosarcoma. TC was prepared by the ring-opening reaction between amino and epoxy groups by one-pot method, which had the good complexing ability with nucleic acids, reduction-responsive degradability and gene transfection performance. TC/miR-22 combined with volasertib could inhibit proliferation, migration and promote apoptosis of osteosarcoma cells in vitro. The anti-tumor mechanisms were revealed as TC/ miR-22 and volasertib could inhibit the PI3K/Akt signaling pathway synergistically. Furthermore, this strategy showed outstanding tumor suppression performance in animal models of orthotopic osteosarcoma, especially in patient-derived chemo-resistant and chemo-intolerant patient-derived xenograft (PDX) models, which reduced the risk of tumor lung metastasis and overcame drug resistance. Therefore, it has great potential for efficient treatment of metastasis and drug resistance of osteosarcoma by the strategy of localized, sustained delivery of miR-22 using the cationic nanocarriers combined with non-traditional chemotherapy drugs.

Delivery of triptolide with reduction-sensitive polymer nanoparticles for liver cancer therapy on patient-derived xenografts models

Hepatocellular carcinoma(HCC)has become the fourth predominant cause of cancer-related deaths worldwide,and HCC is still one of the worst prognoses for survival as it is poorly responsive to both chemotherapy and surgical treatment due to drug resista nce and great toxic effects.Triptolide(TP),a key ingredient from the traditional Chinese medical herb,has been utilized to treat inflammation and antitumor for centuries.However,investigations of this potent agent have been met with only limited success due to the severe systemic toxicities in patients and low water solubility as well as its high toxicity over the past two decades.Herein,we reported the development of a reduction-responsive drug delive ry system loaded with TP fo r glutathione(GSH)-trigge red drug release for cancer therapy.With the GSH-sensitive TP loaded nanoparticles,the remarkable increases in tumor accumulation and amelioration of drug toxicity in animals are demonstrated,which is likely due to sustained stepwise release of active TP within cancer cells.Moreover,in a patient-derived tumor xenograft model of liver cancer,administration of tritolide nanoparticles enhances the antitumor efficacy relative to administration of free TP.These findings indicate that GSH-sensitive release of TP may be a promising strategy for cancer treatment.

Personalized treatment based on mini patient-derived xenografts and WES/RNA sequencing in a patient with metastatic duodenal adenocarcinoma

Background:Treatment guidelines for a variety of cancers have been increasingly used in clinical practice,and have resulted in major improvement in patient outcomes.However,recommended regimens(even first-line treat-ments)are clearly not ideal for every patients.In the present study,we used mini patient-derived xenograft(mini-PDX)and next-generation sequencing to develop personalized treatment in a patient with metastatic duodenal adenocarcinoma.Methods:Resected metachronous metastatic tumor tissues were implanted into SCID mice to determine the sensitivity to a variety of drug regimens.Mutation profiles were assessed using both DNA whole-exome sequencing(DNA-WES)and RNA sequencing.The results of the analyses were used to select optimal treatment for the patient with metastatic duodenal adenocarcinoma.Results:Assessment with mini-PDX models took only 7 days.The results showed high sensitivity to S-1 plus cis-platin,gemcitabine plus cisplatin and everolimus alone.The patient received gemcitabine plus cisplatin initially,but the treatment was terminated due to toxicity.The patient was then switched to treatment with S-1 alone.The overall disease-free survival was 34 months.DNA-WES and RNA sequencing identified KRAS mutation(A146T),TP53(C229Yfs*10)and RICTOR amplification in the metastatic duodenal adenocarcinoma.These findings provided further support to the results of the mini-PDX,and suggest mTOR inhibitors should be used if and when relapse eventually occurs in this patient.Conclusions:Mini-PDX model combined with WES/RNA sequencing can rapidly assess drug sensitivity in cancer patients and reveal key genetic alterations.Further research on this technology for personalized therapy in patients with refractory malignant tumors is warranted.

Characterization of drug responses of mini patient-derived xenografts in mice for predicting cancer patient clinical therapeutic response

Background:Patient-derived organoids and xenografts(PDXs)have emerged as powerful models in functional diag-nostics with high predictive power for anticancer drug response.However,limitations such as engraftment failure and time-consuming for establishing and expanding PDX models followed by testing drug efficacy,and inability to subject to systemic drug administration for ex vivo organoid culture hinder realistic and fast decision-making in selecting the right therapeutics in the clinic.The present study aimed to develop an advanced PDX model,namely MiniPDX,for rapidly testing drug efficacy to strengthen its value in personalized cancer treatment.Methods:We developed a rapid in vivo drug sensitivity assay,OncoVee®MiniPDX,for screening clinically relevant regimens for cancer.In this model,patient-derived tumor cells were arrayed within hollow fiber capsules,implanted subcutaneously into mice and cultured for 7 days.The cellular activity morphology and pharmacokinetics were systematically evaluated.MiniPDX performance(sensitivity,specificity,positive and negative predictive values)was examined using PDX as the reference.Drug responses were examined by tumor cell growth inhibition rate and tumor growth inhibition rate in PDX models and MiniPDX assays respectively.The results from MiniPDX were also used to evaluate its predictive power for clinical outcomes.Results:Morphological and histopathological features of tumor cells within the MiniPDX capsules matched those both in PDX models and in original tumors.Drug responses in the PDX tumor graft assays correlated well with those in the corresponding MiniPDX assays using 26 PDX models generated from patients,including 14 gastric cancer,10 lung cancer and 2 pancreatic cancer.The positive predictive value of MiniPDX was 92%,and the negative predictive value was 81%with a sensitivity of 80%and a specificity of 93%.Through expanding to clinical tumor samples,Min-iPDX assay showed potential of wide clinical application.Conclusions:Fast in vivo MiniPDX assay based on capsule implantation was developed-to assess drug responses of both PDX tumor grafts and clinical cancer specimens.The high correlation between drug responses of paired MiniPDX and PDX tumor graft assay,as well as translational data suggest that MiniPDX assay is an advanced tool for personalized cancer treatment.

Generation and application of patient-derived xenograft models in pancreatic cancer research

Objective:Pancreatic ductal adenocarcinoma cancer(PDAC)is one of the leading causes of cancer-related death worldwide.Hence,the development of effective anti-PDAC therapies is urgently required.Patient-derived xenograft(PDX)models are useful models for developing anti-cancer therapies and screening drugs for pre&sion medicine.This review aimed to provide an updated summary of using PDX models in PDAC.Data sources:The author retrieved information from the PubMed database up to June 2019 using various combinations of search terms,including PDAC,pancreatic carcinoma,pancreatic cancer,patient-derived xenografts or PDX,and patient-derived tumor xenografts or PDTX.Study selection:Original articles and review articles relevant to the review's theme were selected.Results:PDX models are better than cell line-derived xenograft and other models.PDX models consistently demonstrate retained tumor morphology and genetic stability,are benefi&al in cancer research,could enhance drug discovery and oncologic mechanism development of PDAC,allow an improved understanding of human cancer cell biology,and help guide personalized treatmem.Conclusions:In this review,we outline the status and application of PDX models in both basic and pre-clinical pancreatic cancer researches.PDX model is one of the most appropriate pre-clinical tools that can improve the prognosis of patients with pancreatic cancer in the future.

Patient-derived xenograft platform of OSCC： a renewable human bio-bank for preclinical cancer research and a new co-clinical model for treatment optimization

Advances in next-generation sequencing and bioinformatics have begun to reveal the complex genetic landscape in human cancer genomes, including oral squamous cell carcinoma （OSCC）. Sophisticated preclinical models that fully represent intra- and inter-tumoral heterogeneity are required to understand the molecular diversity of cancer and achieve the goal of personalized therapies. Patient-derived xenograft （PDX） models generated from human tumor samples that can retain the histological and genetic features of their donor tumors have been shown to be the preferred preclinical tool in translational cancer research compared with other conventional preclinical models. Specifically, genetically well-defined PDX models can be applied to accelerate targeted antitumor drug development and biomarker discovery. Recently, we have successfully established and characterized an OSCC PDX panel as part of our tumor bio-bank for translational cancer research. In this paper, we discuss the establishment, characterization, and preclinical applications of the PDX models. In particular, we focus on the classification and applications of the PDX models based on validated annotations, including clinicopathological features, genomic profiles, and pharmacological testing information. We also explore the translational value of this well-annotated PDX panel in the development of co-clinical trials for patient stratification and treatment optimization in the near future. Although various limitations still exist, this preclinical approach should be further tested and improved.

A nanocomposite competent to overcome cascade drug resistance in ovarian cancer via mitochondria dysfunction and NO gas synergistic therapy

Ovarian cancer(OC)is one of the most common and recurring malignancies in gynecology.Patients with relapsed OC always develop"cascade drug resistance"(CDR)under repeated chemotherapy,leading to subsequent failure of chemotherapy.To overcome this challenge,amphiphiles(P1)carrying a nitric oxide(NO)donor(Isosorbide 5-mononitrate,ISMN)and high-density disulfide are synthesized for encapsulatingmitochondria-targeted tetravalent platinum prodrug(TPt)to construct a nanocomposite(INP@TPt).Mechanism studies indicated that INP@TPt significantly inhibited drug-resistant cells by increasing cellular uptake and mitochondrial accumulation of platinum,depleting glutathione,and preventing apoptosis escape through generating highly toxic peroxynitrite anion(ONOO−).To better replicate the microenvironmental and histological characteristics of the drug resistant primary tumor,an OC patient-derived tumor xenograft(PDXOC)model in BALB/c nude mice was established.INP@TPt showed the best therapeutic effects in the PDXOC model.The corresponding tumor tissues contained high ONOO−levels,which were attributed to the simultaneous release of O_(2)^(·−)and NO in tumor tissues.Taken together,INP@TPtbased systematic strategy showed considerable potential and satisfactory biocompatibility in overcoming platinum CDR,providing practical applications for ovarian therapy.

Novel dual inhibitor for targeting PIM1 and FGFR1 kinases inhibits colorectal cancer growth in vitro and patient-derived xenografts in vivo

Colorectal cancer(CRC) is the second most common cause of cancer-related death in the world. The pro-viral integration site for Moloney murine leukemia virus 1(PIM1) is a proto-oncogene and belongs to the serine/threonine kinase family, which are involved in cell proliferation, migration,and apoptosis. Fibroblast growth factor receptor 1(FGFR1) is a tyrosine kinase that has been implicated in cell proliferation, differentiation and migration. Small molecule HCI-48 is a derivative of chalcone, a class of compounds known to possess anti-tumor, anti-inflammatory and antibacterial effects. However,the underlying mechanism of chalcones against colorectal cancer remains unclear. This study reports that HCI-48 mainly targets PIM1 and FGFR1 kinases, thereby eliciting antitumor effects on colorectal cancer growth in vitro and in vivo. HCI-48 inhibited the activity of both PIM1 and FGFR1 kinases in an ATPdependent manner, as revealed by computational docking models. Cell-based assays showed that HCI-48inhibited cell proliferation in CRC cells(HCT-15, DLD1, HCT-116 and SW620), and induced cell cycle arrest in the G2/M phase through modulation of cyclin A2. HCI-48 also induced cellular apoptosis, as evidenced by an increase in the expression of apoptosis biomarkers such as cleaved PARP, cleaved caspase 3 and cleaved caspase 7. Moreover, HCI-48 attenuated the activation of downstream components of the PIM1 and FGFR1 signaling pathways. Using patient-derived xenograft(PDX) murine tumor models,we found that treatment with HCI-48 diminished the PDX tumor growth of implanted CRC tissue expressing high protein levels of PIM1 and FGFR1. This study suggests that the inhibitory effect of HCI-48 on colorectal tumor growth is mainly mediated through the dual-targeting of PIM1 and FGFR1kinases. This work provides a theoretical basis for the future application of HCI-48 in the treatment of clinical CRC.

Integrating of lipophilic platinum(IV) prodrug into liposomes for cancer therapy on patient-derived xenograft model

Platinum-based anticancer agents such as cisplatin and its analogues are widely used for treating multiple cancers. However, due to the inferior water-solubility, chemoresistance and consequent adverse side effects, their clinical applications are limited. Herein, choles Pt(IV), a lipophilic platinum(IV) prodrug was synthesized for manufacture of Choles Pt(IV)-Liposomes aiming to resolve the predefined obstacles encountered by platinum drugs. Following systematic screening, Choles Pt(IV)-Liposomes showed a small particle size(105.6 nm), the rapid release of platinum(Pt) ions, and notable apoptosis of cancer cells.In addition, according to the fluidity and safety results of animal experiments in mice, Choles Pt(IV)-Liposomes also showed better therapeutic effect, which significantly inhibited the growth of patientderived xenograft tumors of hepatocellular carcinoma with an inhibition ratio of 80.7%, and effectively alleviated the drug toxicity brought by traditional platinum drugs. Overall, this study provides a promising route to enhance the therapeutic efficiency of platinum drugs in cancer treatment.

Development of gemcitabine-resistant patient-derived xenograft models of pancreatic ductal adenocarcinoma

Aim:Gemcitabine is a frontline agent for locally-advanced and metastatic pancreatic ductal adenocarcinoma(PDAC),but neither gemcitabine alone nor in combination produces durable remissions of this tumor type.We developed three PDAC patient-derived xenograft(PDX)models with gemcitabine resistance(gemR)acquired in vivo,with which to identify mechanisms of resistance relevant to drug exposure in vivo and to evaluate novel therapies.Methods:Mice bearing independently-derived PDXs received 100 mg/kg gemcitabine once or twice weekly.Tumors initially responded,but regrew on treatment and were designated gemR.We used immunohistochemistry to compare expression of proteins previously associated with gemcitabine resistance[ribonucleotide reductase subunit M1(RRM1),RRM2,human concentrative nucleoside transporter 1(hCNT1),human equilibrative nucleoside transporter 1(hENT1),cytidine deaminase(CDA),and deoxycytidine kinase(dCK)]in gemR and respective gemcitabine-naïve parental tumors.Results:Parental and gemR tumors did not differ in tumor cell morphology,amount of tumor-associated stroma,or expression of stem cell markers.No consistent pattern of expression of the six gemR marker proteins was observed among the models.Increases in RRM1 and CDA were consistent with in vitro-derived gemR models.However,rather than the expected decreases of hCNT1,hENT1,and dCK,gemR tumors expressed no change in or higher levels of these gemR marker proteins than parental tumors.Conclusion:These models are the first PDAC PDX models with gemcitabine resistance acquired in vivo.The data indicate that mechanisms identified in models with resistance acquired in vitro are unlikely to be the predominant mechanisms when resistance is acquired in vivo.Ongoing work focuses on characterizing unidentified mechanisms of gemR and on identifying agents with anti-tumor efficacy in these gemR models。