Resistant Cells Research Articles

Exposure to endocrine disruptor DEHP promotes the progression and radiotherapy resistance of pancreatic cancer cells by increasing BMI1 expression and properties of cancer stem cells

Most patients diagnosed with pancreatic cancer are initially at an advanced stage, and radiotherapy resistance impact the effectiveness of treatment. This study aims to investigate the effects of endocrine disruptor Di-(2-ethylhexyl) phthalate (DEHP) on various biological behaviors and the radiotherapy sensitivity of pancreatic cancer cells, as well as its potential mechanisms. Our findings indicate that exposure to DEHP promotes the proliferation of various cancer cells, including those from the lung, breast, pancreas, and liver, in a time- and concentration-dependent manner. Furthermore, DEHP exposure could influence several biological behaviors of pancreatic cancer cells in vivo and vitro. These effects include reducing cell apoptosis, causing G0/G1 phase arrest, increasing migration capacity, enhancing tumorigenicity, elevating the proportion of cancer stem cells (CSCs), and upregulating expression levels of CSCs markers such as CD133 and BMI1. DEHP exposure can also increase radiation resistance, which can be reversed by downregulating BMI1 expression. In summary our research suggests that DEHP exposure can lead to pancreatic cancer progression and radiotherapy resistance, and the mechanism may be related to the upregulation of BMI1 expression, which leads to the increase of CSCs properties.

Evaluation of Novel Diaza Cage Compounds as MRP Modulators in Cancer Cells.

Novel MRP modulators are needed to combat MRP-mediated multidrug resistance (MDR) in cancer cells. Anticancer drug resistance is the main problem in cancer therapy. Causative multidrug efflux pumps are attractive target structures for the development of inhibitors of their activity. We synthesized novel cage dimeric 1,4-dihydropyridines to evaluate them as MRP modulators in cancer cells targeting MRP1, MRP2, and MRP4. Cage compounds were synthesized by solution dimerization of monomeric 1,4-dihydropyridines and a final functionalization reaction. The MRP modulation was determined in cellular efflux assays by the use of the flow cytometry technique as well as cellular fluorescent measurements with each fluorescent substrate of the efflux pumps. Difluoro phenyl and methoxy or dimethoxy benzyl substitutions were most favourable for the MRP1 and MRP2 inhibition, whereas monofluor phenyl and dimethoxy benzyl substitutions were most favourable for the MRP4 inhibition. Effective inhibitors were identified that were demonstrated to restore the respective cancer cell line sensitivity for the anticancer drug as a proof-of-concept that encourages further preclinical studies.</p>.

Multiplex Determination of Glycan Profiles on Urinary Prostate-Specific Antigen by Quartz-Crystal Microbalance Combined with Surface-Enhanced Raman Scattering.

Prostate cancer remains a major health concern, with prostate-specific antigen (PSA) being a key biomarker for its detection and monitoring. However, PSA levels often fall into a "gray zone", where PSA levels are not clearly indicative of cancer, thus complicating early diagnosis and treatment decisions. Glycosylation profiles, which often differ between healthy and diseased cells, have emerged as potential biomarkers to enhance the specificity and sensitivity of cancer diagnosis in these ambiguous cases. We propose the integration of two complementary techniques, namely quartz-crystal microbalance with dissipation (QCM-D) and surface-enhanced Raman scattering (SERS) to study PSA glycan profiles. QCM-D offers real-time operation, PSA mass quantification, and label-free detection with high sensitivity, as well as enhanced specificity and reduced cross-reactivity when using nucleic acid aptamers as capture ligands. Complementary SERS sensing enables the determination of the glycosylation pattern on PSA, at low concentrations and without the drawbacks of photobleaching, thereby facilitating multiplexed glycosylation pattern analysis. This integrated setup could retrieve a data set comprising analyte concentrations and associated glycan profiles in relevant biological samples, which may eventually improve early disease detection and monitoring. Prostate-specific antigen (PSA), a glycoprotein secreted by prostate epithelial cells, serves as our proof-of-concept analyte. Our platform allows multiplex targeting of PSA multiplex glycosylation profiles of PSA at "gray zone" concentrations for prostate cancer diagnosis. We additionally show the use of SERS for glycan analysis in PSA secreted from prostate cancer cell lines after androgen-based treatment. Differences in PSA glycan profiles from resistant cell lines after androgen-based treatment may eventually improve cancer treatment.

Genomic Amplification of TBC1D31 Promotes Hepatocellular Carcinoma Through Reducing the Rab22A-Mediated Endolysosomal Trafficking and Degradation of EGFR.

Hepatocellular carcinomas (HCCs) are characterized by a vast spectrum of somatic copy number alterations (CNAs); however, their functional relevance is largely unknown. By performing a genome-wide survey on prognosis-associated focal CNAs in 814 HCC patients by an integrative computational framework based on transcriptomic data, genomic amplification is identified at 8q24.13 as a promising candidate. Further evidence is provided that the 8q24.13 amplification-driven overexpression of Rab GTPase activating protein TBC1D31 exacerbates HCC growth and metastasis both in vitro and in vivo through activating Epidermal growth factor receptor (EGFR) signaling. Mechanistically, TBC1D31 acts as a Rab GTPase activating protein to catalyze GTP hydrolysis for Rab22A and then reduces the Rab22A-mediated endolysosomal trafficking and degradation of EGFR. Notably, overexpression of TBC1D31 markedly increases the resistance of HCC cells to lenvatinib, whereas inhibition of the TBC1D31-EGFR axis can reverse this resistance phenotype. This study highlights that TBC1D31 at 8q24.13 is a new critical oncogene, uncovers a novel mechanism of EGFR activation in HCC, and proposes the potential strategies for treating HCC patients with TBC1D31 amplification or overexpression.

DrugFormer: Graph-Enhanced Language Model to Predict Drug Sensitivity.

Drug resistance poses a crucial challenge in healthcare, with response rates to chemotherapy and targeted therapy remaining low. Individual patient's resistance is exacerbated by the intricate heterogeneity of tumor cells, presenting significant obstacles to effective treatment. To address this challenge, DrugFormer, a novel graph-augmented large language model designed to predict drug resistance at single-cell level is proposed. DrugFormer integrates both serialized gene tokens and gene-based knowledge graphs for the accurate predictions of drug response. After training on comprehensive single-cell data with drug response information, DrugFormer model presents outperformance, with higher F1, precision, and recall in predicting drug response. Based on the scRNA-seq data from refractory multiple myeloma (MM) and acute myeloid leukemia (AML) patients, DrugFormer demonstrates high efficacy in identifying resistant cells and uncovering underlying molecular mechanisms. Through pseudotime trajectory analysisunique drug-resistant cellular states associated with poor patient outcomes are revealed. Furthermore, DrugFormer identifies potential therapeutic targets, such as COX8A, for overcoming drug resistance across different cancer types. In conclusion, DrugFormer represents a significant advancement in the field of drug resistance prediction, offering a powerful tool for unraveling the heterogeneity of cellular response to drugs and guiding personalized treatment strategies.

Macrophage-induced Expression of TonEBP/NFAT5 Is Associated With Gefitinib Resistance and Migration in PC-9 Cells.

Macrophages prevail in the microenvironment of several tumors, including non-small-cell lung cancer (NSCLC), where they secrete pro-tumorigenic factors that contribute to cancer progression. This study investigated the role of macrophages on the resistance of epidermal growth factor receptor (EGFR)-mutated NSCLC cells to tyrosine kinase inhibitors (TKIs). EGFR-mutated cell lines PC-9 and HCC827 were cocultured with macrophages and treated with TKIs (erlotinib and gefitinib). The effects of the macrophage-conditioned medium (macrophage CM) on gefitinib resistance and cell migration were also evaluated. Co-culture with macrophages significantly enhanced the resistance to erlotinib and gefitinib in PC-9 and HCC827 cells compared to that in cells cultured independently. Macrophage CM markedly induced gefitinib resistance in PC-9 cells, with maximum resistance observed at 50% CM concentration. This resistance persisted for up to 48 h post-CM removal. Macrophage CM inhibited gefitinib-induced apoptosis, as evidenced by the decreased expression of cleaved caspase-3, PARP, and BIM. Additionally, macrophage CM increased the migration ability of PC-9 cells, as shown by the wound healing and transwell migration assays. Studies have shown that TonEBP is crucial in cancer metastasis and drug resistance; we found that inhibition of TonEBP/NFAT5 expression reduced gefitinib resistance and migration in macrophage CM-induced PC-9 cells, indicating its role as mediator of these effects. Macrophages contribute to TKI resistance and enhance the migration of EGFR-mutated NSCLC cells through mechanisms involving TonEBP/NFAT5. Therefore, targeting TonEBP/NFAT5 represents a potential therapeutic strategy for overcoming macrophage-induced TKI resistance in NSCLC cells.

LncRNA MALAT-1 modulates EGFR-TKI resistance in lung adenocarcinoma cells by downregulating miR-125

Molecular targeted therapy resistance remains a major challenge in treating lung adenocarcinoma (LUAD). The resistance of Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs, epidermal growth factor receptor-tyrosine kinase inhibitor) plays a dominant role in molecular targeted therapy. Our previous research demonstrated the role of MALAT-1 (Metastasis-associated lung adenocarcinoma transcript 1) in the formation of Erlotinib-resistant LUAD cells. This study aims to uncover the mechanism of MALAT-1 overexpression in Erlotinib-resistant LUAD cells. The RT2 LncRNA PCR array system was used to explore MALAT-1 regulation in Erlotinib-resistant LUAD cells through patient serum analysis. Dual luciferase reporter experiments confirmed the binding between MALAT-1 and miR-125, leading to regulation of miR-125 expression. Functional assays were performed to elucidate the impact of MALAT1 on modulating drug resistance, growth, and Epithelial-mesenchymal transition (EMT, Epithelial-mesenchymal transition) in both parental and Erlotinib-resistant LUAD cells. The investigation unveiled the mechanism underlying the competing endogenous RNA (ceRNA, competing endogenouse RNA) pathway. MALAT1 exerted its regulatory effect on miR-125 as a competing endogenous RNA (ceRNA). Moreover, MALAT1 played a role in modulating the sensitivity of LUAD cells to Erlotinib. Rab25 was identified as the direct target of miR-125 and mediated the functional effects of MALAT1 in Erlotinib-resistant LUAD cells. In conclusion, our study reveals overexpress MALAT-1 cause the drug resistance of EGFR-TKIs in non-small cell lung cancer (NSCLC) through the MALAT-1/miR-125/Rab25 axis. These findings present a potential novel therapeutic target and perspective for the treatment of LUAD.

Metal-polyphenol-network coated R612F nanoparticles reduce drug resistance in hepatocellular carcinoma by inhibiting stress granules

Stress granules (SGs) are considered to be the nonmembrane discrete assemblies present in the cytoplasm to cope with various environmental stress. SGs can promote the progression and drug resistance of hepatocellular carcinoma (HCC). Therefore, it is important to explore the mechanism of SG formation to reduce drug resistance in HCC. In this study, we demonstrate that p110α is required for SGs assembly. Mechanistically, the Arg-Gly (RG) motif of p110α is required for SG competence and regulates the recruitment of SG components. The methylation of p110α mediated by protein arginine methyltransferase 1 (PRMT1) interferes with the recruitment of p110α to SG components, thereby inhibiting the promotion of p110α to SGs. On this basis, we generated metal-polyphenol-network-coated R612F nanoparticles (MPN-R612F), which can efficiently enter HCC cells and maintain the hypermethylation state of p110α, thereby inhibiting the assembly of SGs and ultimately reducing the resistance of HCC cells to sorafenib. The combination of MPN-R612F nanoparticles and sorafenib can kill HCC cells more effectively and play a stronger anti-tumor effect. This study provides a new perspective for targeting SGs in the treatment of HCC.

Downregulation of UGT2B15 and UGT2B17 contributes to acquired androgen antagonist resistance in prostate cancer cells

Downregulation of UGT2B15 and UGT2B17 contributes to acquired androgen antagonist resistance in prostate cancer cells

Other Diagnostic Tests for Young-Onset Type 2 Diabetes Mellitus

We have read with interest the article entitled “A Cross-sectional Study to Evaluate Beta Cell Function in Individuals with Newly Diagnosed Young-Onset Type 2 Diabetes Mellitus and its Complications,”1 elevated C-peptide levels are indicative of both insulin resistance and beta cell malfunction. These factors are directly linked to the development of complications associated with young-onset Type 2 Diabetes Mellitus (YO-T2DM), including obesity, hypertension, and diabetic kidney disease. The present letter aims to expand the current diagnostic testing options for early detection of YO-T2DM.

Resensitization to colistin results in rapid and stable recovery of adherence, serum resistance and ompW in Acinetobacter baumannii.

Colistin resistance in Acinetobacter baumannii is an emerging problem that limits antimicrobial therapy options. We isolated two pairs of colistin susceptible and colistin-resistant A. baumannii (K1007/K1006 and K408/K409) from two patients diagnosed with carbapenem-resistant A. baumannii infection. Colistin susceptible isolates were exposed to in vitro colistin induction for 50 generations. The selected cell populations were subjected to DNA and RNA sequencing and phenotypic assays. In the in vitro induction assay, K408 gained colistin resistance on the corresponding day of clinical resistance (K408-G25) and got resensitized to colistin in the consecutive generation (K408-G26). A significant upregulation of ompW, ata, adeFGH genes on K408-G25 was followed by a downregulation upon resensitization to colistin (G26). Despite the upregulation of the ompW gene in transcriptomic analysis, the ompW protein disappeared on K408-G25 and recovered in the resensitized generation (G26). In parallel, disrupted cell membrane integrity recovered in K408-G26. In the K408-G25, downregulation of pbpG and upregulation of pbp1a/pbp3 genes decreased serum-resistance which was reversed in the resensitized generation (G26). The K1007 did not gain colistin resistance amongst 50-generations, however, the generation corresponding to clinical resistance day (K1007-G9) had a similar trend with K408-G25. The clinical colistin-resistant K409 and K1006 had SNPs on pmrA and pmrB genes. In this study, we observed that A. baumannii regulates adhesion, efflux pumps and serum-resistance associated genes as an early response to colistin stress. Besides, the ompW protein disappears in the cell membrane of colistin resistant cells which recovers after resensitization to colistin. The lack of ompW protein in colistin-resistant cells should be taken into consideration for escape mutants in development of antivirulence vaccination or treatment options.

Rational Design of a Multi-epitope Vaccine Using Neoantigen Against Colorectal Cancer Through Structural Immunoinformatics and ML-Enabled Simulation Approach.

Colorectal cancer poses a substantial global health burden. Regarding WHO, the global burden of colorectal cancer will be about 3.2 million new cases by the year 2040. Simultaneously, it indicated that this cancer will cause 6 million deaths per year. Despite advancements in chemotherapy and monoclonal antibody therapy, the disease remains a significant challenge due to the resistance of cancer stem cells. This study endeavors to design a multi-epitopic peptide (9-mer epitopes) neoantigen-based vaccine targeting the TLR4/MD2 complex as a potential vaccine candidate. These tumor-specific neoantigens (TSA) are considered novel antigens that can be used for vaccine development against cancer. To develop the neoantigen vaccine candidate, we used the SPENCER database, and 140 lncRNA-derived epitopes were retrieved. From 140 epitopes, we selected seven neoantigens with high antigenic properties for the vaccine construct. A novel vaccine containing epitopes, linkers(EAAAK and CPCPG), and adjuvants(ribosomal [50S]protein L7L12) was formulated utilizing immunoinformatics tools. The vaccine's biophysical properties were evaluated, revealing its antigenicity(0.6469), stability(instability index:37.05), and potential for immune system interaction. In-depth structural analyses, molecular docking studies, and ML-enabled immune simulation profiling underscored the vaccine's structural integrity, binding affinity with TLR4, and ability to elicit robust immune responses against colorectal cancer antigens. These findings suggest that the multi-epitopic vaccine holds promise as a next-generation approach to combat colorectal cancer. Our in silico studies exhibit potentiality of the vaccine candidate; however, further in vivo and in vitro investigations are crucial to validate immunogenicity, safety, and efficacy before clinical implementation. Our study developed a first-time lncRNA-derived neoantigen-based cancer vaccine.

Engineered probiotic ameliorates ulcerative colitis by restoring gut microbiota and redox homeostasis

Probiotics are potential treatments for ulcerative colitis (UC), but their efficacy is frequently compromised by gastrointestinal conditions that limit adhesion and activity. Here, we use machine learning and bioinformatics to confirm that patients with UC have decreased prevalence of Lactobacillus genus and increased oxidative stress, which correlate with inflammation severity. Accordingly, we developed a probiotic-based therapeutic that synergistically restores intestinal redox and microbiota homeostasis. Lactobacillus casei (Lac) were induced to form a pericellular film, providing a polysaccharide network for spatially confined crystallization of ultrasmall but highly active selenium dots (Se-Lac). Upon oral administration, the selenium dot-embedded pericellular film efficiently enhanced gastric acid resistance and intestinal mucoadhesion of Lac cells. At the lesion site, the selenium dots scavenged reactive oxygen species, while Lac modulated the gut microbiota. In multiple mouse models and non-human primates, this therapeutic effectively relieved inflammation and reduced colonic damage, thus showing promise as a UC treatment.

Advancements in Hydrogel-Based Therapies for Ovarian Cancer: A Review.

Ovarian cancer, the most deadly gynecologic malignancy, is often resistant to conventional antitumor therapy due to various factors such as severe side effects, unexpected recurrence, and significant tissue damage. The limitations of current treatments and the resistance of invasive tumor cells contribute to these challenges. Hydrogel therapy has recently emerged as a potential treatment option for ovarian cancer, offering advantages such as controllability, biocompatibility, high drug loading capacity, prolonged drug release, and responsiveness to specific stimuli. Hence, the utilization of biodegradable hydrogels as carriers for chemotherapeutic agents has emerged as a significant concern in the field. Injectable hydrogel-based drug delivery systems, in particular, have demonstrated superior efficacy compared to traditional systemic chemotherapy for cancer treatment. The pliability of hydrogel therapy allows for access to anatomical regions that may be challenging for surgical intervention. This review article examines recent advancements in the application of hydrogels for diagnosing and treating ovarian cancer, while also proposing a novel direction for the use of hydrogel technology in this context. The objective of this article is to offer a novel point of reference and serve as a source of inspiration for the advancement of more precise and individualized cancer therapies.

Radiation-induced YAP/TEAD4 binding confers non-small cell lung cancer radioresistance via promoting NRP1 transcription

Despite the importance of radiation therapy as a non-surgical treatment for non-small cell lung cancer (NSCLC), radiation resistance has always been a concern, due to poor patient response and prognosis. Therefore, it is crucial to uncover novel targets to enhance radiotherapy and investigate the mechanisms underlying radiation resistance. Previously, we demonstrated that NRP1 was connected to radiation resistance in NSCLC cells. In the present study, bioinformatics analysis of constructed radiation-resistant A549 and H1299 cell models revealed that transcription coactivator YAP is a significant factor in cell proliferation and metastasis. However, there has been no evidence linking YAP and NRP1 to date. In this research, we have observed that YAP contributes to radiation resistance in NSCLC cells by stimulating cell proliferation, migration, and invasion. Mechanistically, YAP dephosphorylation after NSCLC cell radiation. YAP acts as a transcription co-activator by binding to the transcription factor TEAD4, facilitating TEAD4 to bind to the NRP1 promoter region and thereby increasing NRP1 expression. NRP1 has been identified as a new target gene for YAP/TEAD4. Notably, when inhibiting YAP binds to TEAD4, it inhibits NRP1 expression, and Rescue experiments show that YAP/TEAD4 influences NRP1 to regulate cell proliferation, metastasis and leading to radiation resistance generation. According to these results, YAP/TEAD4/NRP1 is a significant mechanism for radioresistance and can be utilized as a target for enhancing radiotherapy efficacy.

Ailanthone Increases Cisplatin-induced Apoptosis and Autophagy in Cisplatin Resistance Non-small Cell Lung Cancer Cells through the PI3K/AKT/mTOR Pathway.

The effectiveness of therapy is strongly impacted by the resistance of lung cancer cells to cisplatin. The objective of this research is to characterize the impact of ailanthone on cisplatin resistance in non-small cell lung cancer (NSCLC) and examine any potential in vivo and in vitro molecular pathways. Following treatment of A549/DDP cells with ailanthone and cisplatin, cell survival and apoptosis were measured using flow cytometry and Cell Counting Kit-8 (CCK- 8) assays, respectively. mRFP-GFP-LC3 adenovirus transfection was used to track autophagy, and protein expression levels were analyzed by western blotting. Hematoxylin and eosin (H&E) staining was used after the organs of the mice were removed for in vivo investigations. In A549/DDP cells, ailanthone and cisplatin together induced autophagy and apoptosis in a dose and time-dependent manner (P< 0.05). After receiving combined treatment with ailanthone and cisplatin, the expression levels of cleaved caspase- 3, Bcl-2, cleaved PARP, Beclin1L, and C3B-II were considerably elevated by inhibiting the PI3K/AKT/mTOR signaling pathway. Our findings show that ailanthone, without causing adverse effects in vivo, greatly suppressed the growth of A549/DDP-grafted tumors and improved the anti-tumor efficaciousness of cisplatin. According to this study, ailanthone may increase sensitivity to cisplatin and promote autophagy and death in NSCLC A549/DDP cells through the signaling pathway of PI3K/AKT/mTOR.

DNA damage response-related ncRNAs as regulators of therapy resistance in cancer.

The DNA damage repair (DDR) pathway is a complex signaling cascade that can sense DNA damage and trigger cellular responses to DNA damage to maintain genome stability and integrity. A typical hallmark of cancer is genomic instability or nonintegrity, which is closely related to the accumulation of DNA damage within cancer cells. The treatment principles of radiotherapy and chemotherapy for cancer are based on their cytotoxic effects on DNA damage, which are accompanied by severe and unnecessary side effects on normal tissues, including dysregulation of the DDR and induced therapeutic tolerance. As a driving factor for oncogenes or tumor suppressor genes, noncoding RNA (ncRNA) have been shown to play an important role in cancer cell resistance to radiotherapy and chemotherapy. Recently, it has been found that ncRNA can regulate tumor treatment tolerance by altering the DDR induced by radiotherapy or chemotherapy in cancer cells, indicating that ncRNA are potential regulatory factors targeting the DDR to reverse tumor treatment tolerance. This review provides an overview of the basic information and functions of the DDR and ncRNAs in the tolerance or sensitivity of tumors to chemotherapy and radiation therapy. We focused on the impact of ncRNA (mainly microRNA [miRNA], long noncoding RNA [lncRNA], and circular RNA [circRNA]) on cancer treatment by regulating the DDR and the underlying molecular mechanisms of their effects. These findings provide a theoretical basis and new insights for tumor-targeted therapy and the development of novel drugs targeting the DDR or ncRNAs.

Nine new nor-3,4-seco-dammarane triterpenoids from the leaves of Cyclocarya paliurus and their hypoglycemic activity

This manuscript describes the isolation of nine new nor-3,4-seco-dammarane triterpenoids, norqingqianliusus A-I (1–9) and one known nortriterpenoid (10) from Cyclocarya paliurus leaves. Norqingqianliusus A and B (1 and 2) possess a unique 3,4-seco-dammarane-type C26 tetranortriterpenoid skeleton. The compounds were structurally characterized through modern spectroscopic techniques. Moreover, the potential mechanism of hypoglycemic activity was further explored by studying the effects on glucosamine-induced insulin resistant HepG2 cells. In vitro hypoglycemic effects of all of the isolates were investigated using insulin resistant HepG2 cells. The glucose consumption was significantly promoted by compound 10, in a dose-dependent manner, thus alleviating damage in IR-HepG2 cells. Besides, it reduced the PEPCK and GSK3β gene expression, involved in glucose metabolism. The anti-diabetic effects of the plant, utilized traditionally, can hence be attributed to the presence of nor-3,4-seco-dammarane triterpenoids in the leaves.

CCL5/CCR5/CYP1A1 pathway prompts liver cancer cells to survive in the combination of targeted and immunological therapies.

Combination therapy of anti-programmed cell death protein-1 (PD-1) antibodies and tyrosine kinase inhibitors (TKIs) has significantly improved the prognosis for hepatocellular carcinoma (HCC), but many patients still have unsatisfactory outcomes. CD8 T cells are known to exert a pivotal function in the immune response against tumors. Nevertheless, most CD8 T cells in HCC tissues are in a state of exhaustion, losing the cytotoxic activity against malignant cells. Cytokines, mainly secreted by immune cells, play an important role in the occurrence and development of tumors. Here, we demonstrated the changes in exhausted CD8T cells during combination therapy by single-cell RNA sequencing (scRNA-seq) analysis on tumor samples before and after treatment. Combination therapy exerted a substantial impact on the exhausted CD8T cells, particularly in terms of cytokine expression. CCL5 was the most abundantly expressed cytokine in CD8T cells and exhausted CD8T cells, and its expression increased further after treatment. Subsequently, we discovered the CCL5/CCR5/CYP1A1 pathway through RNA sequencing (RNA-seq) on CCL5-stimulated Huh7 cells and verified through a series of experiments that this pathway can mediate the resistance of liver cancer cells to lenvatinib. Tissue experiments showed that after combination therapy, the CCL5/CCR5/CYP1A1 pathway was activated, which can benefit the residual tumor cells to survive treatment. Tumor-bearing mouse experiments demonstrated that bergamottin (BGM), a competitive inhibitor of CYP1A1, can enhance the efficacy of both lenvatinib and combination therapy. Our research revealed one mechanism by which hepatoma cells can survive the combination therapy, providing a theoretical basis for the refined treatment of HCC.

Multi-omics analysis delineates resistance mechanisms associated with BRAF inhibition in melanoma cells

Mutant BRAF is a critical oncogenic driver in melanoma, making it an attractive therapeutic target. However, the success of targeted therapy using BRAF inhibitors vemurafenib and dabrafenib has been limited due to development of resistance, restricting their clinical efficacy. A prior knowledge of resistance mechanisms to BRAFi or any cancer drug can lead to development of drugs that overcome resistance thus improving clinical outcomes. In vitro cellular models are powerful systems that can be utilized to mimic and study resistance mechanisms. In this study, we employed a multi-omics approach to characterize a panel of BRAF mutant melanoma cell lines to develop and systematically characterize BRAFi persister and resistant cells using exome sequencing, proteomics and phosphoproteomics. Our datasets revealed frequently observed intrinsic and acquired, genetic and non-genetic mechanisms of BRAFi resistance that have been studied in patients who developed resistance. In addition, we identified proteins that can be potentially targeted to overcome BRAFi resistance. Overall, we demonstrate that in vitro systems can be utilized not only to predict resistance mechanisms but also to identify putative therapeutic targets.