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.

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.

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.

Establishment of various biliary tract carcinoma cell lines and xenograft models for appropriate preclinical studies

We recently reported several driver genes of biliary tract carcinoma(BTC) that are known to play important roles in oncogenesis and disease progression. Although the need for developing novel therapeutic strategies is increasing, there are very few BTC cell lines and xenograft models currently available for conducting preclinical studies. Using a total of 88 surgical BTC specimens and 536 immunodeficient mice, 28 xenograft models and 13 new BTC cell lines, including subtypes, were established. Some of our cell lines were found to be resistant to gemcitabine, which is currently the first choice of treatment, thereby allowing highly practical preclinical studies to be conducted. Using the aforementioned cell lines and xenograft models and a clinical pathological database of patients undergoing BTC resection, we can establish a preclinical study system and appropriate parameters for drug efficacy studies to explore new biomarkers for practical applications in the future studies.

Combination Therapy of Capecitabine with Cyclophosphamide as a Second-Line Treatment after Failure of Paclitaxel plus Bevacizumab Treatment in a Human Triple Negative Breast Cancer Xenograft Model

We examined the antitumor efficacy of the capecitabine (CAPE) plus cyclophosphamide (CPA) combination as a 2nd-line therapy after paclitaxel (PTX) plus bevacizumab (BEV) treatment in a xenograft model of human triple negative breast cancer (TNBC) cell line, MX-1. After tumor growth was confirmed, PTX (20 mg/kg;i.v.) + BEV (5 mg/kg;i.p.) treatment was started (Day 1). Each agent was administered once a week for 5 weeks and tumor regression was observed for at least the first 3 weeks. For 2nd-line treatment, we selected mice in which the tumor volume had increased from day 29 to day 36 and was within 130 - 250 mm3 on day 36. After randomization of mice selected on day 36, CPA (10 mg/kg;p.o.) and CAPE (539 mg/kg;p.o.) were administered daily for 14 days (days 36 - 49), followed by cessation of the drugs for 1 week. The tumor growth on day 57 was significantly suppressed in the CPA, CAPE and CAPE + CPA groups as compared with the control group (p < 0.05). Furthermore, the antitumor activity on day 57 of CAPE + CPA was significantly stronger than that of CPA or CAPE alone (p < 0.05). The thymidine phosphorylase (TP) level in tumor tissue was evaluated by immunohistochemistry on day 50, and was significantly higher in the CPA group than those in the control group (p < 0.05). Upregulation of TP in tumor tissues by CPA treatment would increase the 5-FU level in tumor tissues treated with CAPE. This would explain the possible mechanism that made CAPE + CPA superior to CAPE alone in the 2nd-line treatment. Our preclinical results suggest that the CAPE + CPA combination therapy may be effective as 2nd-line therapy after disease progression in PTX + BEV 1st-line treatment for TNBC patients.

STI571 combined with vincristine greatly suppressed the tumor formation of multidrug-resistant K562 cells in a human-nude mice xenograft model

Background The development of the targeted signal transduction inhibitor STI571 has prompted us to treat chronic myeloid leukemia in different ways. Since STI571 may reverse multidrug-resistance of K562/MDR cells in vitro, we studied the effect of STI571 on multidrug-resistant K562 cells in vivo. Methods Multidrug-resistant human leukemia cell line K562-n/VCR expresses both bcr/abl fusion gene and multi-drug resistance （mdrl） gene. It is a vincristine resistant cell line subcloned from the vincristine （VCR） sensitive cell line K562-n induced by vincristine in vitro. K562-n and K562-n/VCR cells were inoculated subcutaneously into both sides of nude mice breast （5×10^6 cells/each） to establish a human leukemia xenograft model. The incidence and volume of tumor were observed. In the tumor-bearing nude mice, anti-tumor drugs vincristine, daunorubicin （DNR）, STI571, and STI571 plus VCR for the treatment of mdrl and bcr/abl double positive leukemia were studied respectively. Results The tumor incidence was 100% in the nude mice inoculated with either K562-n or K562-n/VCR. The transcription of the mdrl gene and expression of P-gp were negative in K562-n cells but positive in K562-n/VCR cells. The intracellular accumulation of DNR in K562-n cells was higher than that in K562-n/VCR cells （P〈0.05） The tumor incidence of K562-n/VCR cells in nude mice was much higher than that of K562-n cells in chemotherapy groups, and the mean volume of the tumors was also larger （P〈0.05）. STI571 combined with VCR significantly suppressed the proliferation of K562-n/VCR cells. Conclusions The MDR characteristics of K562-n/VCR in vivo were the same as in vitro. STI571 had a significant tumor-suppressing effect on VCR-sensitive leukemia ceils and a moderate effect on MDR leukemia cells. VCR combined with STI571 had an excellent tumor-suppressing effect on both K562-n/VCR and K562-n in the human-nude mice xenograft model.

SPA: A Quantitation Strategy for MS Data in Patient-derived Xenograft Models

With the development of mass spectrometry(MS)-based proteomics technologies,patient-derived xenograft(PDX),which is generated from the primary tumor of a patient,is widely used for the proteome-wide analysis of cancer mechanism and biomarker identification of a drug.However,the proteomics data interpretation is still challenging due to complex data deconvolution from the PDX sample that is a cross-species mixture of human cancerous tissues and immunodeficient mouse tissues.In this study,by using the lab-assembled mixture of human and mouse cells with different mixing ratios as a benchmark,we developed and evaluated a new method,SPA(shared peptide allocation),for protein quantitation by considering the unique and shared peptides of both species.The results showed that SPA could provide more convenient and accurate protein quantitation in human–mouse mixed samples.Further validation on a pair of gastric PDX samples(one bearing FGFR2 amplification while the other one not)showed that our new method not only significantly improved the overall protein identification,but also detected the differential phosphorylation of FGFR2 and its downstream mediators(such as RAS and ERK)exclusively.The tool pdx SPA is freely available at https://github.com/LiLab-Proteomics/pdx SPA.

Advances in prostate cancer research models:From transgenic mice to tumor xenografting models

The identification of the origin and molecular characteristics of prostate cancer(PCa)has crucial implications for personalized treatment.The development of effective treatments for PCa has been limited;however,the recent establishment of several transgenicmouse lines and/or xenografting models is better reflecting the disease in vivo.With appropriate models,valuable tools for elucidating the functions of specific genes have gone deep into prostate development and carcinogenesis.In the present review,we summarize a number of important PCa research models established in our laboratories(PSA-Cre-ERT2/PTEN transgenic mouse models,AP-OX model,tissue recombination-xenografting models and PDX models),which represent advances of translational models from transgenic mouse lines to human tumor xenografting.Better understanding of the developments of these models will offer new insights into tumor progression and may help explain the functional significance of genetic variations in PCa.Additionally,this understanding could lead to new modes for curing PCa based on their particular biological phenotypes.

Murine models based on acute myeloid leukemia-initiating stem cells xenografting

Acute myeloid leukemia(AML) is an aggressive malignant disease defined by abnormal expansion of myeloid blasts. Despite recent advances in understanding AML pathogenesis and identifying their molecular subtypes based on somatic mutations, AML is still characterized by poor outcomes, with a 5-year survival rate of only 30%-40%, the majority of the patients dying due to AML relapse. Leukemia stem cells(LSC) are considered to be at the root of chemotherapeutic resistance and AML relapse. Although numerous studies have tried to better characterize LSCs in terms of surface and molecular markers, a specific marker of LSC has not been found, and still the most universally accepted phenotypic signature remains the surface antigens CD34+CD38- that is shared with normal hematopoietic stem cells. Animal models provides the means to investigate the factors responsible for leukemic transformation, the intrinsic differences between secondary post-myeloproliferative neoplasm AML and de novo AML, especially the signaling pathways involved in inflammation and hematopoiesis. However, AML proved to be one of the hematological malignancies that is difficult to engraft even in the most immunodeficient mice strains, and numerous ongoing attempts are focused to develop "humanized mice" that can support the engraftment of LSC. This present review is aiming to in-troduce the field of AML pathogenesis and the concept of LSC, to present the current knowledge on leukemic blasts surface markers and recent attempts to develop best AML animal models.

肺癌小鼠模型研究进展

肺癌是世界上发病率和死亡率最高的恶性肿瘤之一,明确其病因、发病机制及药物防治方法是目前研究热点。小鼠是肺癌临床前研究中最常用的实验动物,根据不同的研究策略和目的选择合适的小鼠模型。目前常用的小鼠肺癌模型包括诱发性模型、移植物模型及基因工程模型等,根据研究目的选择不同的小鼠模型。回顾国内外肺癌小鼠模型相关文献报道,归纳总结常用肺癌小鼠模型的研究进展,为肺癌研究提供参考。

Berberine retarded the growth of gastric cancer xenograft tumors by targeting hepatocyte nuclear factor 4α

BACKGROUND Gastric cancer is the third deadliest cancer in the world and ranks second in incidence and mortality of cancers in China.Despite advances in prevention,diagnosis,and therapy,the absolute number of cases is increasing every year due to aging and the growth of high-risk populations,and gastric cancer is still a leading cause of cancer-related death.Gastric cancer is a consequence of the complex interaction of microbial agents,with environmental and host factors,resulting in the dysregulation of multiple oncogenic and tumor-suppressing signaling pathways.Global efforts have been made to investigate in detail the genomic and epigenomic heterogeneity of this disease,resulting in the identification of new specific and sensitive predictive and prognostic biomarkers.Trastuzumab,a monoclonal antibody against the HER2 receptor,is approved in the first-line treatment of patients with HER2+tumors,which accounts for 13%-23%of the gastric cancer population.Ramucirumab,a monoclonal antibody against VEGFR2,is currently recommended in patients progressing after first-line treatment.Several clinical trials have also tested novel agents for advanced gastric cancer but mostly with dis-appointing results,such as anti-EGFR and anti-MET monoclonal antibodies.Therefore,it is still of great significance to screen specific molecular targets for gastric cancer and drugs directed against the molecular targets.AIM To investigate the effect and mechanism of berberine against tumor growth in gastric cancer xenograft models and to explore the role of hepatocyte nuclear factor 4α(HNF4α)-WNT5a/β-catenin pathways played in the antitumor effects of berberine.METHODS MGC803 and SGC7901 subcutaneous xenograft models were established.The control group was intragastrically administrated with normal saline,and the berberine group was administrated intragastrically with 100 mg/kg/d berberine.The body weight of nude mice during the experiment was measured to assess whether berberine has any adverse reaction.The volume of subcutaneous tumors during this experiment was recorded to evaluate the inhibitory effect of berberine on the growth of MGC803 and SGC7901 subcutaneous transplantation tumors.Polymerase chain reaction assays were conducted to evaluate the alteration of transcriptional expression of HNF4α,WNT5a andβ-catenin in tumor tissues and liver tissues from the MGC803 and SGC7901 xenograft models.Western blotting and IHC were performed to assess the protein expression of HNF4α,WNT5a andβ-catenin in tumor tissues and liver tissues from the MGC803 and SGC7901 xenograft models.RESULTS In the both MGC803 and SGC7901 xenograft tumor models,berberine significantly reduced tumor volume and weight and thus retarded the growth rate of tumors.In the SGC7901 and MGC803 subcutaneously transplanted tumor models,berberine down-regulated the expression of HNF4α,WNT5a andβ-catenin in tumor tissues from both transcription and protein levels.Besides,berberine also suppressed the protein expression of HNF4α,WNT5a andβ-catenin in liver tissues.CONCLUSION Berberine retarded the growth of MGC803 and SGC7901 xenograft model tumors,and the mechanism behind these anti-growth effects might be the downregulation of the expression of HNF4α-WNT5a/β-catenin signaling pathways both in tumor tissues and liver tissues of the xenograft models.

桂枝茯苓胶囊联合戈舍瑞林对子宫肌瘤大鼠模型醛酮还原酶1C3和内分泌的影响

目的观察桂枝茯苓胶囊联合戈舍瑞林对子宫肌瘤大鼠模型醛酮还原酶1C3(AKR1C3)和内分泌的影响。方法将36只7周龄雌性白细胞介素-2受体共同Υ链(IL2RG)大鼠随机分为空白对照组、模型对照组和联合治疗组,每组各12只。模型对照组和联合治疗组通过雌孕激素药物建立子宫肌瘤模型。造模结束后第2天,空白对照组和模型对照组予蒸馏水5 mL灌胃,联合治疗组予桂枝茯苓胶囊混悬液0.70 g/(kg·d)+戈舍瑞林1.25 mg/(kg·d)灌胃,连续6周。采用酶联免疫吸附法测定各组大鼠血清雌二醇、孕酮和催乳素水平,实时荧光定量聚合酶链式反应法检测AKR1C3 mRNA表达,蛋白免疫印迹法检测Ⅰ型胶原、转化生长因子β(TGF-β)、纤溶酶原激活物抑制剂-1(PAI-1)、半胱氨酸天冬氨酸蛋白酶-3(Caspase-3)、B淋巴细胞瘤-2(Bcl-2)、Bcl-2相关X蛋白(Bax)蛋白表达。结果与空白对照组相比,模型对照组雌二醇、孕酮和催乳素含量均升高(P<0.05);与模型对照组相比,联合治疗组雌二醇、孕酮和催乳素含量降低(P<0.05)。与空白对照组相比,模型对照组AKR1C3 mRNA表达含量升高(P<0.05);与模型对照组相比,联合治疗组AKR1C3 mRNA表达含量降低(P<0.05)。与空白对照组相比,模型对照组Ⅰ型胶原、PAI-1和TGF-β蛋白表达均升高(P<0.05);与模型对照组相比,联合治疗组Ⅰ型胶原、PAI-1和TGF-β蛋白表达均降低(P<0.05)。与空白对照组相比,模型对照组Caspase-3和Bax蛋白表达降低(P<0.05),Bcl-2蛋白表达升高(P<0.05);与模型对照组相比,联合治疗组Caspase-3和Bax蛋白表达升高(P<0.05),Bcl-2蛋白表达降低(P<0.05)。结论桂枝茯苓胶囊联合戈舍瑞林能降低子宫肌瘤大鼠雌二醇、孕酮和催乳素水平,抑制AKR1C3表达,具有抗增殖和促凋亡的作用,可抑制子宫肌瘤生长。

Mouse models of pancreatic cancer

Pancreatic cancer is one of the most lethal of human malignancies ranking 4th among cancer-related death in the western world and in the United States,and potent therapeutic options are lacking.Although during the last few years there have been important advances in the understanding of the molecular events responsible for the development of pancreatic cancer,currently specific mechanisms of treatment resistance remain poorly understood and new effective systemic drugs need to be developed and probed.In vivo models to study pancreatic cancer and approach this issue remain limited and present different molecular features that must be considered in the studies depending on the purpose to fit special research themes.In the last few years,several genetically engineered mouse models of pancreatic exocrine neoplasia have been developed.These models mimic the disease as they reproduce genetic alterations implicated in the progression of pancreatic cancer.Genetic alterations such as activating mutations in KRas,or TGFb and/or inactivation of tumoral suppressors such as p53,INK4A/ARF BRCA2 and Smad4 are the most common drivers to pancreatic carcinogenesis and have been used to create transgenic mice.These mouse models have a spectrum of pathologic changes,from pancreatic intraepithelial neoplasia to lesions that progress histologically culminating in fully invasive and metastatic disease and represent the most useful preclinical model system.These models can characterize the cellular and molecular pathology of pancreatic neoplasia and cancer and constitute the best tool to investigate new therapeutic approaches,chemopreventive and/or anticancer treatments.Here,we review and update the current mouse models that reproduce different stages of human pancreatic ductal adenocarcinoma and will have clinical relevance in future pancreatic cancer developments.

Evolution of Tumor Model: From Animal Model of Tumor to Tumor Model in Animal

Patient derived xenograft (PDX) is defined as a growth of patients’ tumor in the xenograft setting. The evolution of cancer model in animal has a century old history. The most single reason that exerted the pressure on the traditional animal model of cancer to evolve to PDX is that the traditional models have not delivered as expected and traditional models have not predicted clinical success. In spite of well above 50 drugs developed and approved for oncology over the last several decades, there remains a nirking paucity of clinical success as a reminder that this war on cancer riding on the animal model is far from won. In a backbreaking attempt to analyze the failure, the limitation of the “model” system appeared to be the most rational cause of this shortcoming. It was more of a failure to test a drug rather than a failure to make a drug that stunted our collective growth and success in cancer research. PDX is the product of this age-old failure and its fitness is currently tested in virtually all organ-type solid tumors. This review will present and appraise PDX model in the context of its evolution, its future promise, its limitations and more specifically, the current content of PDX in different solid tumors including breast, lung, colorectal, prostrate, GBM, pancreatic, hepatocellular carcinoma and melanoma.

An improved model of heterotopic cardiac xenotransplantation from guinea－pig to rat

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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.

应用新型免疫缺陷型NCG小鼠建立患者来源急性T淋巴细胞白血病模型的研究

目的:将患者来源的急性T淋巴细胞白血病(T-ALL)细胞接种于NCG小鼠,建立稳定的人类T-ALL白血病动物模型。方法:分离初诊T-ALL患者骨髓来源的白血病细胞,鉴定后经尾静脉接种于NCG小鼠。定期采用流式细胞术检测小鼠外周血中hCD45阳性的细胞比例,通过病理及免疫组化检测小鼠骨髓、肝脏、脾脏等脏器组织白血病细胞浸润情况。第一代小鼠模型建立成功后,取脾脏细胞接种于第二代小鼠,第二代小鼠模型建立成功后取脾脏细胞进一步接种于第三代小鼠,定期采用流式细胞术监测各组小鼠外周血白血病细胞生长情况,以评估此T-ALL白血病动物模型的稳定性。结果:第一代小鼠在接种d 10可在外周血中检测到hCD45阳性的白血病细胞,其后比例逐渐增高,平均第6-7周小鼠出现精神萎靡,小鼠外周血及骨髓涂片可见大量T淋巴细胞白血病细胞。小鼠脾脏明显肿大,免疫组织化学检测结果显示hCD3阳性的白血病细胞广泛浸润骨髓、肝脏、脾脏等。第二代、第三代小鼠能稳定发生白血病,平均生存期为4-5周。结论:采用T-ALL患者骨髓来源的白血病细胞,经尾静脉接种于NCG小鼠,可以成功构建患者来源的肿瘤细胞异种移植(PDTX)模型。

小檗碱通过激活自噬诱导caspase依赖性凋亡发挥抗结直肠癌作用

目的探究小檗碱通过自噬依赖性凋亡发挥抗结直肠功效的潜在作用机制。方法使用HCT116细胞和移植瘤模型小鼠进行小檗碱抗肿瘤药效和可能作用机制的研究。体外研究中,通过利用CCK8实验评价小檗碱对结直肠癌细胞活力的影响,使用细胞克隆实验评价小檗碱对结直肠癌细胞增殖的影响,同时借助流式细胞术和TUNEL染色法对小檗碱诱导结直肠癌细胞凋亡作用进行研究。透射电镜和mCherry-GFP-LC3B腺病毒转染细胞用于检测细胞内自噬流变化。通过对小鼠组织进行HE染色、免疫组化染色和TUNEL染色,评价小檗碱体内抗结直肠癌作用。结果体外研究结果表明,小檗碱能够抑制结直肠癌细胞活力,诱导细胞凋亡,同时提高细胞内LC3B水平。使用自噬抑制剂3-MA、CQ和BafA1进行干预,自噬抑制剂能够促进HCT116细胞生长,抵消小檗碱诱导的结直肠癌细胞凋亡作用。雷帕霉素增强小檗碱上调HCT116细胞中LC3B水平的作用,同时Z-VAD-FMK或ATG siRNA能够废除小檗碱诱导结直肠癌细胞凋亡的作用。在体研究结果表明,小檗碱能够降低肿瘤体积和重量,引起肿瘤组织发生凋亡。进一步的体内作用机制研究结果表明,小檗碱显著抑制p-mTOR表达,同时显著上调ATG5、ATG7、cleaved-caspase3和cleaved-caspase8表达。结论小檗碱能够通过诱导结直肠癌细胞发生自噬,促进其发生caspase依赖性凋亡,进而抑制结直肠癌细胞增殖。

人源肿瘤异种移植小鼠模型研究进展

建立适当的移植瘤模型对于癌症研究至关重要。迄今为止,最常用的移植瘤模型是人源肿瘤细胞系异种移植模型(cancer cell line-based xenograft,CDX),即将体外传代培养的肿瘤细胞移植到免疫缺陷小鼠体内形成移植瘤。虽然这种模型容易建立且建模周期较短,但不能充分代表临床癌症患者,因此,具有能够稳定保留肿瘤异质性的人源肿瘤异种移植模型(patient-derived tumor xenograft,PDX)在诸多应用中开始代替CDX模型。PDX模型通过将患者组织或原代细胞直接植入免疫缺陷小鼠进行成瘤,这种方式保留亲代肿瘤的组织病理学、分子特征和药物反应性,可作为临床前模型,在药物筛选、生物标志物开发和联合临床试验等方面具有显著优势。在这篇综述中,我们将详细介绍PDX模型的构建方法和应用,总结模型建立过程中及进行临床前研究中可能遇到的问题。