Risk of hepatitis B virus reactivation in oncological patients treated with tyrosine kinase inhibitors:A case report and literature analysis

Hepatitis B virus(HBV)reactivation(HBVr)represents a severe and potentially life-threatening condition,and preventive measures are available through blood test screening or prophylactic therapy administration.The assessment of HBVr traditionally considers factors such as HBV profile,including hepatitis B surface antigen(HBsAg)and antibody to hepatitis B core antigen,along with type of medication(chemotherapy;immunomodulants).Nevertheless,consideration of possible patient’s underlying tumor and the specific malignancy type(solid or hematologic)plays a crucial role and needs to be assessed for decision-making process.

Advanced Lung Adenocarcinoma with EGFR 19-del Mutation Transformed into SCC after EGFR-tyrosine Kinase inhibitors Treatment:A Case report

BACKGROUND Epidermal growth factor receptor tyrosine kinase inhibitors(EGFR-TKIs)significantly improve the survival of patients with Epidermal growth factor receptor(EGFR)sensitive mutations in non-small cell lung cancer(NSCLC).CASE SUMMARY A 67-year-old female patient in advanced lung adenocarcinoma suffered from drug resistance after EGFR-TKIs treatment.Secondary pathological tissue biopsy confirmed squamous cell carcinoma(SCC)transformation.Patients inevitably encountered drug resistance issues after receiving EGFR-TKIs treatment for a certain period of time,while EGFR-TKIs can significantly improve the survival of patients with EGFR-sensitive mutations in NSCLC.Notably,EGFR-TKIs resistance includes primary and acquired.Pathological transformation is one of the mechanisms of acquired resistance in EGFR-TKIs,with SCC transformation being relatively rare.Our results provide more detailed results of the patient’s diagnosis and treatment process on SCC transformation after EGFR-TKIs treatment for lung adenocarcinoma.CONCLUSION Squamous cell carcinoma transformation is one of the acquired resistance mechanisms of EGFR-TKIs in advanced lung adenocarcinoma with EGFR mutations.

Advances in MET tyrosine kinase inhibitors in gastric cancer

Gastric cancer is among the most frequently occurring cancers and a leading cause of cancer-related deaths globally.Because gastric cancer is highly heterogenous and comprised of different subtypes with distinct molecular and clinical characteristics,the management of gastric cancer calls for better-defined,biomarker-guided,molecular-based treatment strategies.MET is a receptor tyrosine kinase mediating important physiologic processes,such as embryogenesis,tissue regeneration,and wound healing.However,mounting evidence suggests that aberrant MET pathway activation contributes to tumour proliferation and metastasis in multiple cancer types,including gastric cancer,and is associated with poor patient outcomes.As such,MET-targeting therapies are being actively developed and promising progress has been demonstrated,especially with MET tyrosine kinase inhibitors.This review aims to briefly introduce the role of MET alterations in gastric cancer and summarize in detail the current progress of MET tyrosine kinase inhibitors in this disease area with a focus on savolitinib,tepotinib,capmatinib,and crizotinib.Building on current knowledge,this review further discusses existing challenges in MET alterations testing,possible resistance mechanisms to MET inhibitors,and future directions of MET-targeting therapies.

Navigating the complex terrain of hepatitis B virus reactivation in the era of Bruton tyrosine kinase inhibitors

In this editorial,we offer a summary of the risk associated with hepatitis B reactivation(HBVr)in the setting of both solid and hematologic malignancies treated with Bruton tyrosine kinase(BTK)inhibitors,with insights derived from current studies.Furthermore,we emphasize the critical need for a framework regarding robust risk evaluation in patients undergoing such treatments.This framework is essential for identifying those at increased risk of HBVr,enabling healthcare providers to implement proactive measures to prevent reactivation and ensure the safe administration of BTK inhibitor therapy.

Optimal sequential therapy using tyrosine kinase inhibitors as the first-line treatment in patients with metastatic renal cell carcinoma: A nationwide multicenter study

Objective:The purpose of the study was to identify the best sequence of therapy beginning with a tyrosine kinase inhibitor(TKI)as the first-line therapy for patients with metastatic renal cell carcinoma(mRCC)in terms of overall survival(OS),progression-free survival(PFS),and rates of discontinuation and adverse effects during the treatment period.Methods:This is a retrospective,nationwide multicenter study of patients with mRCC after diagnosis at 10 different tertiary medical centers in Korea from January 1992 to December 2017.We focused on patients at either“favorable”or“intermediate”risk according to the International mRCC Database Consortium criteria,and they were followed up(median 335 days).Finally,a total of 1409 patients were selected as the study population.We generated a Cox proportional hazard model adjusted for covariates,and the different therapy schemes were statistically tested in terms of OS as well as PFS.In addition,frequencies of discontinuation and adverse events were compared among the therapy schemes.Results:Of the primary patterns of treatment sequences(24 sequences),“sunitinib epazopanib”and“sunitinibeeverolimuseimmunotherapy”showed the most beneficial results in both OS and PFS with significantly lower hazards than“sunitinib”,which is the most commonly treated agent in Korea.Considering that the“TKIeTKI”structure showed relatively higher discontinuation rates with higher adverse effects,the overall beneficial sequence would be“sunitinibeeverolimuseimmunotherapy”.Conclusion:Among several sequential therapy starting with TKIs,“sunitinibeeverolimuse immunotherapy”was found to be the best scheme for mRCC patients with“favorable”or“intermediate”risks.

Piperlongumine in combination with EGFR tyrosine kinase inhibitors for the treatment of lung cancer cells

Objectives:EGFR tyrosine kinase inhibitor(EGFR-TKI)therapies such as erlotinib and gefitinib are approved for the treatment of non-small cell lung cancer(NSCLC).However,the high incidence of acquired resistance to these EGFR-TKIs may preclude their effectiveness.Piperlongumine(PPL),an extract from the long pepper fruit(Piper longum),has been shown to possess anticancer properties.The purpose of the study was to investigate piperlongumine as an anticancer agent and to study a combination treatment approach with EGFR-TKIs against lung cancer cells.Methods:Anticancer efficacy of PPL,erlotinib(ERL),gefitinib(GEF),and cisplatin(CIS)were investigated in H1299 and H1975 cell lines.Cells were treated with PPL,ERL,GEF,and CIS alone,and in combination,cell viability was determined after 72 h.The mechanism of PPL-induced cytotoxicity was investigated via reactive oxygen species(ROS)induction,and apoptosis induction using acridine orange/ethidium bromide staining and flow cytometry.The effect of treatment on EGFR-mediated oncogenic signaling was investigated by immunoblotting for mitogenic and apoptotic markers.Results:PPL exhibited a potent cytotoxic effect in H1299 and H1975 cells compared to ERL,GEF,and CIS.Combination treatments of PPL with GEF and ERL showed significant reductions in cancer cells compared to control in both cell lines,which were associated with apoptotic induction,but without significant ROS induction.Compared to control,PPL with GEF significantly increased apoptotic cell death in H1975as confirmed with flow cytometry.Treatment with PPL alone and in combination induced anti-mitogenic and apoptotic responses at the molecular level.Conclusion:PPL sensitized lung cancer cells to EGFR-TKI and induced potent cytotoxic effects at low concentrations.

Clinical significance of upregulated Rho GTPase activating protein 12 causing resistance to tyrosine kinase inhibitors in hepatocellular carcinoma

BACKGROUND Hepatocellular carcinoma(HCC)is a major health challenge with high incidence and poor survival rates in China.Systemic therapies,particularly tyrosine kinase inhibitors(TKIs),are the first-line treatment for advanced HCC,but resistance is common.The Rho GTPase family member Rho GTPase activating protein 12(ARHGAP12),which regulates cell adhesion and invasion,is a potential therapeutic target for overcoming TKI resistance in HCC.However,no studies on the expression of ARHGAP12 in HCC and its role in resistance to TKIs have been reported.AIM To unveil the expression of ARHGAP12 in HCC,its role in TKI resistance and its potential associated pathways.METHODS This study used single-cell RNA sequencing(scRNA-seq)to evaluate ARHGAP12 mRNA levels and explored its mechanisms through enrichment analysis.CellChat was used to investigate focal adhesion(FA)pathway regulation.We integrated bulk RNA data(RNA-seq and microarray),immunohistochemistry and proteomics to analyze ARHGAP12 mRNA and protein levels,correlating with clinical outcomes.We assessed ARHGAP12 expression in TKI-resistant HCC,integrated conventional HCC to explore its mechanism,identified intersecting FA pathway genes with scRNA-seq data and evaluated its response to TKI and immunotherapy.RESULTS ARHGAP12 mRNA was found to be highly expressed in malignant hepatocytes and to regulate FA.In malignant hepatocytes in high-score FA groups,MDK-[integrin alpha 6(ITGA6)+integrinβ-1(ITGB1)]showed specificity in ligand-receptor interactions.ARHGAP12 mRNA and protein were upregulated in bulk RNA,immunohistochemistry and proteomics,and higher expression was associated with a worse prognosis.ARHGAP12 was also found to be a TKI resistance gene that regulated the FA pathway.ITGB1 was identified as a crossover gene in the FA pathway in both scRNA-seq and bulk RNA.High expression of ARHGAP12 was associated with adverse reactions to sorafenib,cabozantinib and regorafenib,but not to immunotherapy.CONCLUSION ARHGAP12 expression is elevated in HCC and TKI-resistant HCC,and its regulatory role in FA may underlie the TKI-resistant phenotype.

Advanced lung adenocarcinoma with EGFR 19-del mutation transforms into squamous cell carcinoma after EGFR tyrosine kinase inhibitor treatment

In this editorial we comment on the article by Ji et al.We focus specifically on the EGFR tyrosine kinase inhibitor(EGFR-TKI)treatment and the development of drug resistance to EGFR-TKIs.

Effect of a novel tyrosine kinase inhibitor nintedanib on bFGF and VEGF concentrations in a rabbit retinal vein occlusion model

AIM:To evaluate whether a novel tyrosine kinase inhibitor nintedanib could inhibit basic fibroblast growth factor(bFGF)and vascular endothelial growth factor(VEGF)simultaneously for retinal vascular disease in vivo.METHODS:After a laser induced rabbit retinal vein occlusion(RVO)model was made,0.5 mg of nintedanib was injected intravitreally in the left eye on the third day while the right eye was as a control.Intracameral samples were taken on the day before laser treatment and days 1,3,7,14,21,and 28 after treatment.Enzyme-linked immunosorbent assay(ELISA)was used to test the bFGF and VEGF-A concentrations in the aqueous humor.RESULTS:Both bFGF and VEGF-A rose significantly on the third day after laser treatment in both eyes.In the control eye the bFGF concentration peaked on the 14th day while the VEGF-A concentration dropped rapidly soon after the third day.After nintadanib injection in the study eye,both bFGF and VEGF-A showed a significant reduction on the 4th day(7th day after laser treatment)when compared to the control eye,and kept on low level in the following several weeks.CONCLUSION:Intravitreal injection of nintedanib can inhibit the expression of bFGF and VEGF in the process of RVO model to a certain extent,which is expected to become a new method for the treatment of retinal vascular diseases or fibrotic diseases.

Tyrosine kinase inhibitors and human epidermal growth factor receptor-2 positive breast cancer

The body of evidence investigating human epidermal growth factor receptor-2(HER2)directed therapy in patients with breast cancer(BC)has been growing within the last decade.Recently,the use of tyrosine kinase inhibitors(TKIs)has been of particular interest in the treatment of human malignancies.This literature commentary is intended to highlight the most recent findings associated with the widely-studied TKI agents and their clinical significance in improving the outcomes of HER2 positive BC.

Rituximab combined with Bruton tyrosine kinase inhibitor to treat elderly diffuse large B-cell lymphoma patients: Two case reports

BACKGROUND Diffuse large B-cell lymphoma(DLBCL)is a common aggressive non-Hodgkin's lymphoma(NHL),accounting for 30%-40%of adult NHLs.This report aims to explore the efficacy and safety of rituximab combined with Bruton tyrosine kinase inhibitors(BTKis)in the treatment of elderly patients with DLBCL.CASE SUMMARY The clinical data of two elderly patients with DLBCL who received rituximab combined with BTKi in our hospital were retrospectively analyzed,and the literature was reviewed.The patients were treated with chemotherapy using the R-miniCHOP regimen for two courses.Then,they received rituximab in combination with BTKi.CONCLUSION The treatment experience in these cases demonstrates the potential efficacy of rituximab combined with BTKi to treat elderly DLBCL patients,thus providing a new treatment strategy.

Inhibitory effects of regorafenib, a multiple tyrosine kinase inhibitor, on corneal neovascularization

AIM:To evaluate the inhibitory effects of regorafenib(BAY 73-4506),a multikinase inhibitor,on corneal neovascularization(NV).METHODS:Thirty adult male Sprague-Dawley rats weighing 250-300 g,were used.Corneal NV was induced by NaOH in the left eyes of each rat.Following the establishment of alkali burn,the animals were randomized into five groups according to topical treatment.Group 1(n=6)received 0.9%NaCl,Group 2(n=6)received dimethyl sulfoxide,Group 3(n=6)received regorafenib 1 mg/mL,Group 4(n=6)received bevacizumab 5 mg/mL and Group 5(n=6)received 0.1%dexamethasone phosphate.On the 7d,the corneal surface covered with neovascular vessels was measured on photographs as the percentage of the cornea’s total area using computer-imaging analysis.The corneas obtained from rats were semiquantitatively evaluated for caspase-3 and vascular endothelial growth factor by immunostaining.RESULTS:A statistically significant difference in the percent area of corneal NV was found among the groups(P【0.001).Although the Group 5 had the smallest percent area of corneal NV,there was no difference among Groups 3,4 and 5(P】0.005).There was a statistically significant difference among the groups in apoptotic cell density(P=0.002).The staining intensity of vascular endothelial growth factor in the epithelial and endothelial layers of cornea was significantly different among the groups(P【0.05).The staining intensity of epithelial and endothelial vascular endothelial growth factor was significantly weaker in Groups 3,4 and 5 thanin Groups 1 and 2.CONCLUSION:Topical administration of regorafenib 1mg/mL is partly effective for preventing alkali-induced corneal NV in rats.

Efficacy of EGFR Tyrosine Kinase Inhibitors in Non-small Cell Lung Cancer Patients Harboring Different Types of EGFR Mutations:A Retrospective Analysis

With the development of molecular pathology, many types of epidermal growth factor receptor（EGFR） mutations have been identified. The efficacy of EGFR tyrosine kinase inhibitors（EGFR-TKIs） in non-small cell lung cancer（NSCLC） patients with different types of EGFR mutations, especially in patients with single rare mutations or complex mutations（co-occurrence of two or more different mutations）, has not been fully understood. This study aimed to examine the efficacy of EGFR-TKIs in NSCLC patients with different types of EGFR mutations. Clinical data of 809 NSCLC patients who harbored different types of EGFR mutations and treated from January 2012 to October 2016 at Renmin Hospital and Zhongnan Hospital, Wuhan, were retrospectively reviewed. The clinical characteristics of these patients and the efficacy of EGFR-TKIs were analyzed. Among these patients, 377 patients had only the EGFR del-19 mutation, 362 patients the EGFR L858R mutation in exon 21, 33 patients single rare mutations and 37 patients complex mutations. Among these 809 patients, 239 patients were treated with EGFR-TKIs. In all the 239 patients, the disease control rate（DCR） was 93.7% with two patients（0.2%） achieving complete response（CR）, the median progression free survival（PFS） was 13.0 months（95% confidence interval [CI], 11.6–14.4 months）, and the median overall survival（OS） was 55.0 months（95% CI, 26.3–83.7 months）. Subgroup analysis revealed that the DCR in patients harboring single rare or complex mutations of EGFR was significantly lower than in those with del-19 or L858 R mutation（P〈0.001）. Patients with classic mutations（del-19 and/or L858 R mutations） demonstrated longer PFS（P〈0.001） and OS（P=0.017） than those with uncommon mutations（single rare and/or complex mutations）. Furthermore, the patients with single rare mutations had shorter median OS than in those with other mutations. Multivariate Cox regression analysis identified that the type of EGFR mutations was an independent risk factor for PFS（hazard ratio [HR]=0.308, 95% CI, 0.191–0.494, P〈0.001） and OS（HR=0.221, 95% CI, 0.101–0.480, P〈0.001）. The results suggest that the single rare or complex EGFR mutations confer inferior efficacy of EGFR-TKIs treatment to the classic mutations. The prognosis of the single rare EGFR mutations is depressing. EGFR-TKIs may be not a good choice for NSCLC patients with single rare mutations of EGFR. Further studies in these patients with uncommon mutations（especially for the patients with single rare mutations） are needed to determine a better precision treatment.

Immediate Versus Delayed Treatment with EGFR Tyrosine Kinase Inhibitors after First-line Therapy in Advanced Non-small-cell Lung Cancer

Objective： To analyze the outcomes of patients who received TKI immediately after the first-line without progression as maintenance treatment （immediate group） vs. those received delayed treatment upon disease progression as second-line therapy （delayed group）. Methods： The study included 159 no-small-cell lung cancer （NSCLC） patients who received gefitinib or erlotinib as maintenance treatment in the immediate group （85 patients） or as second-line therapy in the delayed group （74 patients）. The primary end point was progression-free survival （PFS）. EGFR mutation status was detected using denaturing high-performance liquid chromatography （DHPLC）. Results： PFS was 17.3 and 16.4 months in the immediate and delayed groups, respectively （hazard ratio [HR], 0.99; 95% Confidence Interval [CI]： 0.69-1.42; P=0.947）. In a subgroup analysis that included only patients with EGFR mutation, however, PFS was significantly longer in the immediate group than in the delayed group （HR, 0.48; 95% CI： 0.27-0.85; P=0.012）. In patients with wild type EGFR, the risk for disease progression was comparable between the two groups （HR, 1.23; 95% CI： 0.61-2.51; P=0.564）. No significant difference was demonstrated between the immediate and delayed group in terms of the overall survival （OS） （26.1 months vs. 21.6 months, respectively; HR=0.53; 95% CI： 0.27 to 1.06; P=0.072）. There was also no difference in the incidence of adverse events between the two groups. Conclusions： EGFR TKI maintenance improves PFS in patients with EGFR mutation. Prospectively designed clinical studies that compare TKI immediate vs. delayed treatment after first-line chemotherapy upon disease progression are needed.

Predictive indicators of successful tyrosine kinase inhibitor discontinuation in patients with chronic myeloid leukemia

Clinical trials have demonstrated that some patients with chronic myeloid leukemia(CML)treated for several years with tyrosine kinase inhibitors(TKIs)who have maintained a molecular response can successfully discontinue treatment without relapsing.Treatment free remission(TFR)can be reached by approximately 50%of patients who discontinue.Despite having similar levels of deep molecular response and an identical duration of treatment,the factors that influence the successful discontinuation of CML patients remain to be determined.In this review we will explore the factors identified to date that can help predict whether a patient will successfully achieve TFR.We will also discuss the need for the identification of predictive biomarkers associated with a high probability of achieving TFR for the future personalized identification of patients who are suitable for the discontinuation of TKI treatment.

Tyrosine Kinase Inhibitors against Cancer: Their Safety in 216 Moroccan Patients

Tyrosine kinase inhibitors (TKIs) have become a prominent option in the therapeutic arsenal of several cancers. The safety of these drugs has shown various toxicities with varying frequency and severity between different agents. The aim of this study is to describe the safety profile of different classes of TKI used in various solid tumors. It is a retrospectively descriptive study conducted in the Department of Medical Oncology at Hassan II University Hospital of Fez, Morocco, over a period of 6 years from April 2013 until April 2019. It included 216 patients who received one or more TKI for different indications in solid tumors. The average age in our series was 61.4 years with a sex ratio F/M of 1.07. Among the most used TKIs in our department according to their availability: Imatinib (32%) and sunitinib (32%). All patients received one or more tyrosine kinase inhibitors according to the indication. Kidney cancer was the most common malignancy (36%), followed by gastrointestinal stromal tumors (33%). The median duration of treatment was 15 months with extremes of 1 month and 102 months. The main side effects were: Cutaneous in 43% of patients. Digestive toxicity occurred in 36% of cases. Hematotoxicity was reported in 33% of cases. The safety profile of TKIs used in our study was comparable to their global tolerance reported in literature. More studies are needed to investigate the relationship between their toxicity and their efficacy in Moroccan population.

The efficacy of Kanglaite injection during treatment with tyrosine kinase inhibitor in elderly patients with non-small cell lung cancer

Objective Epidermal growth factor receptor–tyrosine kinase inhibitors(EGFR–TKIs) are widely used in the treatment of EGFR mutation-positive non-small cell lung cancer(NSCLC) patients. The Kanglaite injection(KLT) is a novel broad-spectrum anti-cancer injection produced from traditional Chinese medicinal herbs(coix seed). After its approval in 1995, KLT has become the most popular anti-cancer drug in China. As of this writing, no standard treatment guideline is available for elder patients with NSCLC, and the role of traditional Chinese medicinal herbs, including KLT, combined with TKI treatment remains unknown. This retrospective study evaluated the efficacy and safety of KLT in elderly NSCLC patients during TKI treatment.Methods Thirty elderly patients aged 71-79 years with histopathologically confirmed NSCLC attending the General Hospital of the Shenyang Military Region were enrolled in the study and received EGFR-TKI treatment. All participants received 200 m L KLT injections at the same time on days 1–21. Erlotinib(150 mg) or gefitinib(250 mg) was administered daily from days 1 to 21, and the cycle was repeated every 21 days. The endpoint of the primary study was the disease control rate.Results Thirty elderly patients were enrolled in this study. The objective response rate was 21.3% [95% confidence interval(CI): 8.6% to 35.2%], whereas the disease control rate was 80.4%(95% CI: 71.8% to 97.0%). The grade 3 or 4 adverse effects included leucopenia(13.7%), neutropenia(13.4%), anemia(2.9%), and nausea or vomiting(2.7%). Conclusion The administration of KLT combined with erlotinib or gefitinib showed high efficacy in elderly NSCLC patients. The adverse effects of the drug combination were well tolerated by the patients. KLT combined with TKI treatment might provide a satisfactory therapeutic strategy for elderly NSCLC patients.

Antitumor activity of aumolertinib, a third-generation EGFR tyrosine kinase inhibitor, in non-small-cell lung cancer harboring uncommon EGFR mutations

Uncommon epidermal growth factor receptor(EGFR) mutations account for 10% 20% of all EGFR mutations in non-small-cell lung cancer(NSCLC). The uncommon EGFR-mutated NSCLC is associated with poor clinical outcomes and generally achieved unsatisfactory effects to the current therapies using standard EGFR-tyrosine kinase inhibitors(TKIs), including afatinib and osimertinib. Therefore, it is necessary to develop more novel EGFR-TKIs to treat uncommon EGFR-mutated NSCLC.Aumolertinib is a third-generation EGFR-TKI approved in China for treating advanced NSCLC with common EGFR mutations. However, it remains unclear whether aumolertinib is effective in uncommon EGFR-mutated NSCLC. In this work, the in vitro anticancer activity of aumolertinib was investigated in engineered Ba/F3 cells and patient-derived cells bearing diverse uncommon EGFR mutations. Aumolertinib was shown to be more potent in inhibiting the viability of various uncommon EGFR-mutated cell lines than those with wild-type EGFR. And in vivo, aumolertinib could also significantly inhibit tumor growth in two mouse allograft models(V769-D770insASV and L861Q mutations) and a patientderived xenografts model(H773-V774insNPH mutation). Importantly, aumolertinib exerts responses against tumors in advanced NSCLC patients with uncommon EGFR mutations. These results suggest that aumolertinib has the potential as a promising therapeutic candidate for the treatment of uncommon EGFR-mutated NSCLC.

Tumor-derived insulin-like growth factor-binding protein-1 contributes to resistance of hepatocellular carcinoma to tyrosine kinase inhibitors

Background:Antiangiogenic tyrosine kinase inhibitors(TKIs)provide one of the few therapeutic options for effective treatment of hepatocellular carcinoma(HCC).However,patients with HCC often develop resistance toward antiangiogenic TKIs,and the underlying mechanisms are not understood.The aim of this study was to determine the mechanisms underlying antiangiogenic TKI resistance in HCC.Methods:We used an unbiased proteomic approach to define proteins that were responsible for the resistance to antiangiogenic TKIs in HCC patients.We evaluated the prognosis,therapeutic response,and serum insulin-like growth factor-binding protein-1(IGFBP-1)levels of 31 lenvatinib-treated HCC patients.Based on the array of results,a retrospective clinical study and preclinical experiments using mouse and human hepatoma cells were conducted.Additionally,in vivo genetic and pharmacological gain-and loss-of-function experiments were performed.Results:In the patient cohort,IGFBP-1 was identified as the signaling molecule with the highest expression that was inversely associated with overall survival.Mechanistically,antiangiogenic TKI treatment markedly elevated tumor IGFBP-1 levels via the hypoxia-hypoxia inducible factor signaling.IGFBP-1 stimulated angiogenesis through activation of the integrinα5β1-focal adhesion kinase pathway.Consequently,loss of IGFBP-1 and integrinα5β1 by genetic and pharmacological approaches re-sensitized HCC to lenvatinib treatment.Conclusions:Together,our data shed light onmechanisms underlying acquired resistance of HCC to antiangiogenic TKIs.Antiangiogenic TKIs induced an increase of tumor IGFBP-1,which promoted angiogenesis through activating the IGFBP-1-integrinα5β1 pathway.These data bolster the application of a new therapeutic concept by combining antiangiogenic TKIs with IGFBP-1 inhibitors.

Mechanisms of tyrosine kinase inhibitor resistance in renal cell carcinoma

Renal cell carcinoma(RCC),the most prevalent type of kidney cancer,is a significant cause of cancer morbidity and mortality worldwide.Antiangiogenic tyrosine kinase inhibitors(TKls),in combination with immune checkpoint inhibitors(ICls),are among the first-line treatment options for patients with advanced RCC.These therapies target the vascular endothelial growth factor receptor(VEGFR)tyrosine kinase pathway and other kinases crucial to cancer proliferation,survival,and metastasis.TKls have yielded substantial improvements in progression-free survival(PFS)and overall survival(OS)for patients with advanced RCC.However,nearly all patients eventually progress on these drugs as resistance develops.This review provides an overview of TKl resistance in RCC and explores different mechanisms of resistance,including upregulation of alternative proangiogenic pathways,epithelial-mesenchymal transition(EMT),decreased intracellular drug concentrations due to efflux pumps and lysosomal sequestration,alterations in the tumor microenvironment including bone marrow-derived cells(BMDCs)and tumor-associated fibroblasts(TAFs),and genetic factors such as single nucleotide polymorphisms(SNPs).A comprehensive understanding of these mechanisms opens the door to the development of innovative therapeutic approaches that can effectively overcome TKl resistance,thereby improving outcomes for patients with advanced RCC.