Chemoresistance In Hepatocellular Carcinoma Research Articles

METTL3 confers oxaliplatin resistance through the activation of G6PD-enhanced pentose phosphate pathway in hepatocellular carcinoma.

Oxaliplatin-based therapeutics is a widely used treatment approach for hepatocellular carcinoma (HCC) patients; however, drug resistance poses a significant clinical challenge. Epigenetic modifications have been implicated in the development of drug resistance. In our study, employing siRNA library screening, we identified that silencing the m6A writer METTL3 significantly enhanced the sensitivity to oxaliplatin in both in vivo and in vitro HCC models. Further investigations through combined RNA-seq and non-targeted metabolomics analysis revealed that silencing METTL3 impeded the pentose phosphate pathway (PPP), leading to a reduction in NADPH and nucleotide precursors. This disruption induced DNA damage, decreased DNA synthesis, and ultimately resulted in cell cycle arrest. Mechanistically, METTL3 was found to modify E3 ligase TRIM21 near the 3'UTR with N6-methyladenosine, leading to reduced RNA stability upon recognition by YTHDF2. TRIM21, in turn, facilitated the degradation of the rate-limiting enzyme of PPP, G6PD, through the ubiquitination-proteasome pathway. Importantly, high expression of METTL3 was significantly associated with adverse prognosis and oxaliplatin resistance in HCC patients. Notably, treatment with the specific METTL3 inhibitor, STM2457, significantly improved the efficacy of oxaliplatin. These findings underscore the critical role of the METTL3/TRIM21/G6PD axis in driving oxaliplatin resistance and present a promising strategy to overcome chemoresistance in HCC.

Aberrant activation of a miR-101–UBE2D1 axis contributes to the advanced progression and chemotherapy sensitivity in human hepatocellular carcinoma

AbstractChemotherapeutic drugs, such as cisplatin (cis-dichlorodiamineplatinum [II], cDDP) and 5-fluorouracil (5Fu), are widely used in transarterial chemoembolization (TACE), which is a standard therapy for patients with hepatocellular carcinoma (HCC). Chemoresistance is a major cause of TACE treatment failure in HCC patients. Our previous studies have identified the expression levels of miR-101 responsive genes, such as EED, EZH2, STMN1 and JUNB, exhibit significant correlation with the occurrence and progression of HCC, while the role of miR-101 responsive gene signatures in the chemoresistance of HCC treatment remains unclear. In this study, we identified ubiquitin-coupled enzyme E2D1 (UBE2D1) as a crucial regulatory factor in the chemoresistance of HCC, which is a direct target of miR-101 and exhibits significant correlation with miR-101-responsive gene signatures. The bioinformatics analysis showed the expression of UBE2D1 was significantly increased in HCC tissues and was closely correlated with the poor prognosis. In addition, we analyzed the role of miR-101/UBE2D1 axis in regulating chemo-sensitive of HCC cells. Our results showed that miR-101 increases the DNA damage and apoptosis of HCC cells by inhibiting the expression of UBE2D1, which in turn increases the sensitivity of HCC cells to cDDP and 5Fu both in vitro and in vivo. Therefore, simultaneous assessment of miR-101 and UBE2D1 expression levels might provide an effective approach in preselecting HCC patients with survival benefit from TACE treatment. Moreover, further elucidation of the underlying molecular mechanisms of the miR-101/UBE2D1 axis could provide novel insight for targeted therapy of HCC.

Dual role of Nrf2 signaling in hepatocellular carcinoma: promoting development, immune evasion, and therapeutic challenges.

Hepatocellular carcinoma (HCC) is the predominant form of liver cancer and ranks as the third leading cause of cancer-related mortality globally. The liver performs a wide range of tasks and is the primary organ responsible for metabolizing harmful substances and foreign compounds. Oxidative stress has a crucial role in growth and improvement of hepatocellular carcinoma (HCC). Nuclear factor erythroid 2 (1)-related factor 2 (Nrf2) is an element that regulates transcription located in the cytoplasm. It controls the balance of redox reactions by stimulating the expression of many genes that depend on antioxidant response elements. Nrf2 has contrasting functions in the normal, healthy liver and HCC. In the normal liver, Nrf2 provides advantageous benefits, while in HCC it promotes harmful effects that support the growth and survival of HCC. Continuous activation of Nrf2 has been detected in HCC and promotes its advancement and aggressiveness. In addition, Activation of Nrf2 may lead to immune evasion, weakening the immune cells' ability to attack tumors and thereby promoting tumor development. Furthermore, chemoresistance in HCC, which is considered a form of stress response to chemotherapy medications, significantly impedes the effectiveness of HCC treatment. Stress management is typically accomplished by activating specific signal pathways and chemical variables. One important element in the creation of chemoresistance in HCC is nuclear factor-E2-related factor 2 (Nrf2). Nrf2 is a transcription factor that regulates the activation and production of a group of genes that encode proteins responsible for protecting cells from damage. This occurs through the Nrf2/ARE pathway, which is a crucial mechanism for combating oxidative stress within cells.

SEC24C suppresses the propagation and chemoresistance of hepatocellular carcinoma by promoting unfolded protein response-related apoptosis.

Cells routinely utilize the unfolded protein response (UPR) to alleviate endoplasmic reticulum (ER)-stress or trigger about apoptotic death under extreme ER-stress conditions. Tumor cells are subjected to persistent ER-stress due to their crowded microenvironment, but can maintain hyperactive proliferation under most stressful conditions. Therefore, understanding strategies employed by cancer cells to escape from UPR-related apoptosis has important medical implications. SEC24 homolog C (SEC24C) was found decreased in later colorectal cancer (CRC) stages, but its exact role in response to ER-stress and activation of UPR in hepatocellular carcinoma (HCC) remains to be elucidated. Here, we have identified the downregulation of SEC24C in human HCC sample and its suppressive role in regulating HCC proliferation and chemoresistance. Mechanistically, SEC24C was found to interact with eukaryotic translation initiation factor 2 alpha kinase 3 (EIF2AK3 or PERK) and activate the downstream UPR-related apoptosis. During this process, SEC24C was observed to be anchored in nucleus under normal condition but responded immediately to ER-stress and could subsequently translocate to the ER. Furthermore, overexpression of SEC24C significantly augmented the efficacy of bortezomib in HCC treatment. In conclusion, our findings revealed a novel role of SEC24C in regulating HCC proliferation and chemoresistance by modulating UPR activation.

Sensitization of hepatocellular carcinoma cells to HDACi is regulated through hsa-miR-342-5p/CFL1

BackgroundIncreased prevalence of hepatocellular carcinoma (HCC) remains a global health challenge. HCC chemoresistance is a clinical obstacle for its management. Aberrant miRNA expression is a hallmark for both cancer progression and drug resistance. However, it is unclear which miRNAs are involved in HCC chemoresistance.MethodsMicroRNA microarray analysis revealed a differential expression profile of microRNAs between the hepatocellular carcinoma HA22T cell line and the HDACi-R cell line, which was validated by quantitative real-time PCR (qRT-PCR). To determine the biological function of miR-342-5p and the mechanism of the microRNA-342-5p/CFL1 axis in hepatocellular carcinoma HDACi resistance, loss- and gain-of-function studies were conducted in vitro.ResultsHere we demonstrated the molecular mechanism of histone deacetylase inhibitor (HDACi) resistance in HCC. Differential miRNA expression analysis showed significant down regulation of miR-342-5p in HDACi-R cells than in parental HA22T cells. Mimics of miR-342-5p enhanced apoptosis through upregulation of Bax, cyto-C, cleaved-caspase-3 expressions with concomitant decline in anti-apoptotic protein (Bcl-2) in HDACi-R cells. Although HDACi did not increase cell viability of HDACi-R, overexpression of miR-342-5p decreased cofilin-1 expression, upregulated reactive oxygen species (ROS) mediated apoptosis, and sensitized HDACi-R to HDACi in a dose-dependent manner.ConclusionOur findings demonstrated the critical role of miR-342-5p in HDACi resistance of HCC and that this mechanism might be attributed to miR-342-5p/cofilin-1 regulation.

Chemotherapy-induced acetylation of ACLY by NAT10 promotes its nuclear accumulation and acetyl-CoA production to drive chemoresistance in hepatocellular carcinoma

Chemotherapeutic efficacy is seriously impeded by chemoresistance in more than half of hepatocellular carcinoma (HCC) patients. However, the mechanisms involved in chemotherapy-induced upregulation of chemoresistant genes are not fully understood. Here, this study unravels a novel mechanism controlling nuclear acetyl-CoA production to activate the transcription of chemoresistant genes in HCC. NAT10 is upregulated in HCC tissues and its upregulation is correlated with poor prognosis of HCC patients. NAT10 is also upregulated in chemoresistant HCC cells. Targeting NAT10 increases the cytotoxicity of chemotherapy in HCC cells and mouse xenografts. Upon chemotherapy, NAT10 translocates from the nucleolus to the nucleus to activate the transcription of CYP2C9 and PIK3R1. Additionally, nuclear acetyl-CoA is specifically upregulated by NAT10. Mechanistically, NAT10 binds with ACLY in the nucleus and acetylates ACLY at K468 to counteract the SQSTM1-mediated degradation upon chemotherapy. ACLY K468-Ac specifically accumulates in the nucleus and increases nuclear acetyl-CoA production to activate the transcription of CYP2C9 and PIK3R1 through enhancing H3K27ac. Importantly, K468 is required for nuclear localization of ACLY. Significantly, ACLY K468-Ac is upregulated in HCC tissues, and ablation of ACLY K468-Ac sensitizes HCC cells and mouse xenografts to chemotherapy. Collectively, these findings identify NAT10 as a novel chemoresistant driver and the blockage of NAT10-mediated ACLY K468-Ac possesses the potential to attenuate HCC chemoresistance.

Sponging of five tumour suppressor miRNAs by lncRNA-KCNQ1OT1 activates BMPR1A/BMPR1B-ACVR2A/ACVR2B signalling and promotes chemoresistance in hepatocellular carcinoma

Diverse mechanisms have been established to understand the chemoresistance of hepatocellular carcinoma (HCC), but the contribution of non-coding RNAs is not surveyed well. Here, we aimed to explore the lncRNA-miRNA axis in Hepatitis C and B virus (HCV and HBV) infected HCC to investigate the molecular mechanism of chemoresistance and to identify a potential therapeutic target for HCC. The small RNA transcriptome analysis followed by qRT-PCR validation with the liver tissues of both HCV and HBV infected HCC patients revealed that miR-424-5p, miR-136-3p, miR-139-5p, miR-223-3p, and miR-375-3p were the most downregulated miRNAs in HCC compared to normal (log2 fold change ≤−1.5, Padj ≤ 0.05). In silico pathway analysis with the validated targets of each miRNA revealed that the signalling pathway regulating pluripotency of stem cells is commonly targeted by these five miRNAs. Subsequent validation by 3′UTR-luciferase assay and western blot analysis unveiled that these five miRNAs impeded either same or diverse genes, but all linked to BMP signalling pathway such as BMPR1A/BMPR1B by miR-139-5p, miR-136-3p, and miR-375-3p, and ACVR2A/ACVR2B by miR-424-5p and miR-223-3p. Furthermore, restoration of each miRNA in Huh7/SNU449 cells inhibited phosphorylation of downstream SMAD1/5 and ERK1/2, and attenuated Epithelial-mesenchymal transition, stemness, spheroid formation, chemoresistance, invasion and migration of cells. To investigate the mechanism of suppression of these miRNAs, “DIANA” tool was employed and lncRNA-KCNQ1OT1 was retrieved as interacting partner of all the five miRNAs. In vitro RNA pull-down assay revealed that lncRNA-KCNQ1OT1 physically interacted and sequestered these five miRNAs in the cytoplasm. Hence, KCNQ1OT1 was suppressed in Huh7/SNU449 cells using CRISPR technology and observed regression of oncogenic properties with enhanced chemosensitivity and reduced metastasis in cancer cells. Shrinkage of tumour size and volume in NOD-SCID mice injected with KCNQ1OT1-sgRNA cells further strengthened our observations. Thus, lncRNA-KCNQ1OT1 is the main regulator, which reduces the level of beneficiary miRNAs in the tumour milieu and modulates BMP signalling pathway to promote chemoresistance in HCC, suggesting lncRNA-KCNQ1OT1 might have robust potential to be a therapeutic target in HCC.

USP3 inhibition is Active Against Chemo-resistant Hepatocellular Carcinoma Anchorage-independent Growth via Suppressing Wnt/β-catenin.

USPs are a family of enzymes that regulate protein degradation, and their dysregulation has been implicated in the development and progression of cancer. This study aimed to determine whether ubiquitin-specific proteases 3 (USP3) could be a potential target for therapy in hepatocellular carcinoma (HCC), particularly in resistant HCC. This study systematically investigated the role of USP3 in HCC, with a focus on chemo-resistant HCC cells. The level of USP3 from clinical samples was measured using an ELISA assay. Cell proliferation, apoptosis, migration, and anchorage-independent colony formation assays were performed. Transfection was performed to knock down USP3 expression and measure β-catenin activity, and real-time PCR was used to measure levels of MYC and CYCLIN D1 genes. USP3 protein was upregulated in HCC tissues, but its upregulation was not associated with clinicopathology. USP3 knockdown had a similar inhibitory effect on growth in both sensitive and resistant HCC cells, did not affect migration, and induced apoptosis in sensitive but not resistant HCC cells. Furthermore, USP3 knockdown was more effective in suppressing anchorage-independent colony formation in chemoresistant HCC cells compared to their chemo-sensitive counterparts. Pearson correlation coefficient analysis revealed a strong positive correlation between USP3 and CTNNB1, and consistently, USP3 knockdown reduced the levels and activities of β-catenin in HCC cells. Using a Wnt activator (lithium) in rescue studies significantly reversed the inhibitory effects of USP3 knockdown. The findings suggest that inhibiting USP3 is an effective strategy against cancer stem cells and chemo-resistant HCC cells.

MicroRNA-302a enhances 5-fluorouracil sensitivity in HepG2 cells by increasing AKT/ULK1-dependent autophagy-mediated apoptosis

Abstract Objectives MicroRNA-302a (miR-302a) has been implicated in the oncogenic processes, but its role in hepatocellular carcinoma (HCC) chemoresistance and related mechanisms are still unclear. Therefore, the aim of this study was to investigate the role of miR-302a in HCC chemoresistance and elucidate its underlying mechanism. Methods In this study, we detected the level of miR-302a in HCC tissues (including chemoresistant and chemosensitive tissues), non-tumor tissues, liver cancer cell lines, and 5-fluorouracil (5-FU)-resistant cells (HepG2/R). Additionally, we conducted cell viability, apoptosis, and autophagy analyses as well as assessed the levels of cleaved caspase-3, cleaved caspase-9, microtubule-associated protein 1 light chain 3 beta II (LC3B-II), Akt, and UNC-51 like kinase 1 (ULK1) in HepG2 cells transfected with miR-302a mimic or inhibitor prior to 5-FU treatment. Lastly, we predicted the target of miR-302a and verified the relationship between miR-302a and Akt by luciferase reporter and functional repair assays. Results Our results revealed that miR-302a was down-regulated in HCC tissues (p<0.01), especially in chemoresistant tissues (p<0.01). Consistently, the miR-302a level exhibited a lower expression in HepG2/R cells compared to their parental cells (p<0.01). Furthermore, the 5-FU-induced apoptosis and autophagy of HepG2 cells were promoted by miR-302a over-expression and diminished by miR-302a inhibition (p<0.01). Target analysis revealed that miR-302a could directly target Akt. Moreover, miR-302a inhibited Akt expression and subsequently elevated ULK1 expression (p<0.01). Inhibition of ULK1 could abrogate the sensitization of overexpressed miR-302a to 5-FU in HepG2 cells (p<0.01). Conclusions Altogether, our results demonstrate that the down-regulation of miR-302a promotes 5-FU resistance in HCC by attenuating the Akt/ULK1 axis-dependent autophagy and apoptosis.

DDR2/STAT3 Positive Feedback Loop Mediates the Immunosuppressive Microenvironment by Upregulating PD-L1 and Recruiting MDSCs in Oxaliplatin-Resistant HCC

Background & aimsTranscriptome sequencing revealed high expression of discoidin domain receptor 2 (DDR2) in oxaliplatin-resistant hepatocellular carcinoma (HCC). This study aimed to explore the role of DDR2 in oxaliplatin resistance and immune evasion in HCC. MethodsOxaliplatin-resistant HCC cell lines were established. The interaction between DDR2 and STAT3 was investigated, along with the mechanisms involved in DDR2/STAT3-mediated PD-L1 upregulation and polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) accumulation both in vitro and in vivo. ResultsDDR2 was found to induce the phosphorylation of STAT3, leading to its nuclear translocation. Conversely, the activation of STAT3 enhanced DDR2 expression. A positive feedback loop involving DDR2/STAT3 was identified in oxaliplatin-resistant HCC, associated with PD-L1 upregulation and PMN-MDSCs accumulation was identified in oxaliplatin-resistant HCC. Knockdown of DDR2 and STAT3 sensitized oxaliplatin-resistant HCC cells to oxaliplatin and resulted in decreased PMN-MDSCs and increased CD8+ T cells in the tumor microenvironment. ELISA array and MDSC transwell migration assays indicated that oxaliplatin-resistant HCC cells recruited PMN-MDSCs through CCL20. Dual luciferase reporter assays demonstrated that STAT3 can directly enhance the transcription of PD-L1 and CCL20. Furthermore, treatment with a PD-L1 antibody in combination with CCL20 blockade had significant antitumor effects on oxaliplatin-resistant HCC. ConclusionsOur findings revealed a positive feedback mechanism involving DDR2 and STAT3 that mediates the immunosuppressive microenvironment and promotes oxaliplatin resistance and immune evasion via PD-L1 upregulation and PMN-MDSCs recruitment. Targeting the DDR2/STAT3 pathway may be a promising therapeutic strategy to overcome immune escape and chemoresistance in HCC.

Targeting PTBP1 blocks glutamine metabolism to improve the cisplatin sensitivity of hepatocarcinoma cells through modulating the mRNA stability of glutaminase.

Hepatocellular carcinoma (HCC) is a frequently diagnosed malignancy with a high mortality rate. Cisplatin (CDDP) is a widely applied anti-cancer drug. However, a large population of liver cancer patients developed CDDP resistance. The polypyrimidine tract binding protein (PTBP1) is an RNA-binding protein involving in progressions of diverse cancers. Here we report PTBP1 was significantly upregulated in liver tumors and cell lines. Silencing PTBP1 effectively sensitized HCC cells to CDDP. From the established CDDP-resistant HCC cell line (HepG2 CDDP Res), we observed that CDDP-resistant cells were more sensitive to CDDP under low glutamine supply compared with that in HCC parental cells. CDDP-resistant HCC cells displayed elevated glutamine metabolism rate. Consistently, PTBP1 promotes glutamine uptake and the glutamine metabolism key enzyme, glutaminase (GLS) expression. Bioinformatics analysis predicted that the 3'-UTR of GLS mRNA contained PTBP1 binding motifs which were further validated by RNA immunoprecipitation and RNA pull-down assays. PTBP1 associated with GLS 3'-UTR to stabilize GLS mRNA in HCC cells. Finally, we demonstrated that the PTBP1-promoted CDDP resistance of HCC cells was through modulating the GLS-glutamine metabolism axis. Summarily, our findings uncovered a PTBP1-mediated CDDP resistance pathway in HCC, suggesting that PTBP1 is a promisingly therapeutic target to overcome chemoresistance of HCC.

Canagliflozin reduces chemoresistance in hepatocellular carcinoma through PKM2-c-Myc complex-mediated glutamine starvation

Cisplatin (CPT) is one of the standard treatments for hepatocellular carcinoma (HCC). However, its use is limits as a monotherapy due to drug resistance, and the underlying mechanism remains unclear. To solve this problem, we tried using canagliflozin (CANA), a clinical drug for diabetes, to reduce chemoresistance to CPT, and the result showed that CANA could vigorously inhibit cell proliferation and migration independent of the original target SGLT2. Mechanistically, CANA reduced aerobic glycolysis in HCC by targeting PKM2. The downregulated PKM2 directly bound to the transcription factor c-Myc in the cytoplasm to form a complex, which upregulated the level of phosphorylated c-Myc Thr58 and promoted the ubiquitination and degradation of c-Myc. Decreased c-Myc reduced the expression of GLS1, a key enzyme in glutamine metabolism, leading to impaired glutamine utilization. Finally, intracellular glutamine starvation induced ferroptosis and sensitized HCC to CPT. In conclusion, our study showed that CANA re-sensitized HCC to CPT by inducing ferroptosis through dual effects on glycolysis and glutamine metabolism. This is a novel mechanism to increase chemosensitivity, which may provide compatible chemotherapy drugs for HCC.

TRIM14 Overexpression Induces Chemoresistance and Malignant Behaviors of Hepatocellular Carcinoma Cells by Activating the STAT3/HIF-1α Pathway.

Members of the tripartite motif (TRIM)-containing protein family have been found to be involved in the progression of hepatocellular carcinoma (HCC). TRIM14 exerts a promotive impact on several cancers. This study aimed to explore the function and mechanism of TRIM14 in HCC. TRIM14 expression in HCC tissues and HCC cell lines was detected. The overexpression or knockdown model of TRIM14 was established in HCC cell lines. Cell Counting Kit-8 (CCK-8) assay, flow cytometry, Transwell assay, RT-PCR, Western blot, and immunofluorescence were performed to verify the influence of TRIM14 on cell proliferation, sensitivity to chemotherapy drugs, apoptosis, migration, invasion, and autophagy. A xenograft tumor model was used to confirm the impact of TRIM14 on tumor cell growth. As shown by the data, TRIM14 level was notably higher in the tumor tissues of HCC patients than in the adjacent tissues. The overall survival rate of patients with a high TRIM14 expression was relatively lower than that of patients with a low TRIM14 expression. TRIM14 upregulation enhanced the proliferation, autophagy, migration, and invasion of HCC cells and chemoresistant HCC cells and decreased apoptosis. TRIM14 knockdown contributed to the opposite effects. In in vivo experiments, TRIM14 upregulation bolstered tumor growth. Western blot analysis revealed that TRIM14 upregulation boosted signal transducer and activator of transcription3 (STAT3) and hypoxia-inducible factor-1alpha (HIF-1α) expression, and TRIM14 knockdown suppressed their expression. Moreover, repressing STAT3 and HIF-1α could mitigate the tumor-promoting role of TRIM14 in HCC cells. Overall, TRIM14 facilitated malignant HCC development and induced chemoresistance in HCC cells by activating the STAT3/HIF-1α axis.

Impact of tumor suppressor genes inactivation on the multidrug resistance phenotype of hepatocellular carcinoma cells

The response of advanced hepatocellular carcinoma (HCC) to pharmacological treatments is unsatisfactory and heterogeneous. Inactivation of tumor suppressor genes (TSGs) by genetic and epigenetic events is frequent in HCC. This study aimed at investigating the impact of frequently altered TSGs on HCC chemoresistance. TSG alterations were screened by in silico analysis of TCGA-LIHC database, and their relationship with survival was investigated. These TSGs were silenced in HCC-derived cell lines using CRISPR/Cas9. TLDA was used to determine the expression of a panel of 94 genes involved in the resistome. Drug sensitivity, cell proliferation, colony formation and cell migration were assessed. The in silico study revealed the down-regulation of frequently inactivated TSGs in HCC (ARID1A, PTEN, CDH1, and the target of p53, CDKN1A). The presence of TP53 and ARID1A variants and the low expression of PTEN and CDH1 correlated with a worse prognosis of HCC patients. In PLC/PRF/5 cells, ARID1A knockout (ARID1AKO) induced increased sensitivity to cisplatin, doxorubicin, and cabozantinib, without affecting other characteristics of malignancy. PTENKO and E-CadKO showed minimal changes in malignancy, resistome, and drug response. In p53KO HepG2 cells, enhanced malignant properties and higher resistance to cisplatin, doxorubicin, sorafenib, and regorafenib were found. This was associated with changes in the resistome. In conclusion, the altered expression and function of several TSGs are involved in the heterogeneity of HCC chemoresistance and other features of malignancy, contributing to the poor prognosis of these patients. Individual identification of pharmacological vulnerabilities is required to select the most appropriate treatment for each patient.

A Review On the Sources and Mechanisms of Chemoresistance in Hepatocellular Carcinoma

Degenerative Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths worldwide, with surgical resection followed by chemotherapy being the primary treatment method. However, the complex nature and high metastatic potential of HCC often render treatment plans ineffective, and acquired drug resistance frequently results in disease relapse in patients. In this review, we conducted an extensive literature search of different databases, including Medline, Scopus, and Cochrane, to identify studies that have addressed chemoresistance in HCC. This article provides a comprehensive knowledge of molecular mechanisms of chemoresistance in HCC, including genetic polymorphism, apoptosis, DNA methylation, tumor suppressor genes, DNA repair, topoisomerases, drug efflux, and epithelial-mesenchymal transition. Understanding these mechanisms is crucial for developing personalized combination therapies, identifying chemosensitive populations, and evaluating the effectiveness of chemotherapeutic agents through cell culture and orthotopic models. Therapies that can counter these resistance mechanisms need to be developed to better manage and control the disease. This would increase the patient survival rate and help decrease the use of multiple chemotherapeutic agents that greatly increase the risk of toxicities encountered by patients. Further studies are needed, so a combined effort by healthcare professionals and pharmaceutical companies can be the key to combatting the ever-rising rate of chemoresistance in HCC.

Editor's Summaries of the Articles Published in This Issue of Molecular Medicine Communications

In this issue Yusuf and colleagues investigated the association of association of fat, mass and obesity (FTO) gene polymorphism with diabetes and prediabetes in Pakistani population, Mannan and colleagues did a variant analysis of FOXE1 gene in non-syndromic cleft lip and palate in Peshawar, Pakistan, Zaib et al determined the frequency of p53 mutations and Epstein-Barr virus in Pakistani gastric cancer patients and investigated their association with the tumor grade, Rehman and her colleagues made an analysis of comparative effectiveness & renoprotective effects of hypoglycemic drugs for type 2 diabetes mellitus, and Ain et al reviewed the sources and mechanisms of chemoresistance in hepatocellular carcinoma.

Spotlights on extracellular vesicles in hepatocellular carcinoma diagnosis and treatment: an update review.

Hepatocellular carcinoma (HCC), one of the most prevalent cancers, with a high mortality rate worldwide, seriously impairs patient health. The lack of accurate targets impedes the early screening and diagnosis of HCC and is associated with a poor response to routine therapies. Extracellular vesicles (EVs), comprising exosomes, microvesicles, and apoptotic bodies, are lipid bilayer membrane-derived nanometer-sized vesicles. EVs can be secreted from various cancer cells and release diverse biomolecules, such as DNA, RNA, proteins, metabolites, and lipids, making them a potential source of biomarkers and regulators of the tumor microenvironment. Emerging evidence suggests that EVs are involved in intercellular communication by carrying biological information. These EVs elicit physiological functions and are involved in the oncogenesis of HCC, such as proliferation, invasion, metastasis, and chemoresistance of HCC. EVs have also been considered promising biomarkers and nanotherapeutic targets for HCC. Therefore, this review sheds light on the current understanding of the interactions between EVs and HCC to propose potential biomarkers and nanotherapeutic strategies.

The functions and roles of C2H2 zinc finger proteins in hepatocellular carcinoma.

C2H2 zinc finger (C2H2-ZF) proteins are the majority group of human transcription factors and they have many different molecular functions through different combinations of zinc finger domains. Hepatocellular carcinoma (HCC) is one of the most prevalent malignant tumors and the main reason for cancer-related deaths worldwide. More and more findings support the abnormal expression of C2H2-ZF protein in the onset and progression of HCC. The C2H2-ZF proteins are involved in various biological functions in HCC, such as EMT, stemness maintenance, metabolic reprogramming, cell proliferation and growth, apoptosis, and genomic integrity. The study of anti-tumor drug resistance also highlights the pivotal roles of C2H2-ZF proteins at the intersection of biological functions (EMT, stemness maintenance, autophagy)and chemoresistance in HCC. The involvement of C2H2-ZF protein found recently in regulating different molecules, signal pathways and pathophysiological activities indicate these proteins as the possible therapeutic targets, and diagnostic or prognostic biomarkers for HCC.

Role of p53 suppression in the pathogenesis of hepatocellular carcinoma.

In the world, hepatocellular carcinoma (HCC) is among the top 10 most prevalent malignancies. HCC formation has indeed been linked to numerous etiological factors, including alcohol usage, hepatitis viruses and liver cirrhosis. Among the most prevalent defects in a wide range of tumours, notably HCC, is the silencing of the p53 tumour suppressor gene. The control of the cell cycle and the preservation of gene function are both critically important functions of p53. In order to pinpoint the core mechanisms of HCC and find more efficient treatments, molecular research employing HCC tissues has been the main focus. Stimulated p53 triggers necessary reactions that achieve cell cycle arrest, genetic stability, DNA repair and the elimination of DNA-damaged cells' responses to biological stressors (like oncogenes or DNA damage). To the contrary hand, the oncogene protein of the murine double minute 2 (MDM2) is a significant biological inhibitor of p53. MDM2 causes p53 protein degradation, which in turn adversely controls p53 function. Despite carrying wt-p53, the majority of HCCs show abnormalities in the p53-expressed apoptotic pathway. High p53 in-vivo expression might have two clinical impacts on HCC: (1) Increased levels of exogenous p53 protein cause tumour cells to undergo apoptosis by preventing cell growth through a number of biological pathways; and (2) Exogenous p53 makes HCC susceptible to various anticancer drugs. This review describes the functions and primary mechanisms of p53 in pathological mechanism, chemoresistance and therapeutic mechanisms of HCC.

Dimeric oxyberberine CT4-1 targets LINC02331 to induce cytotoxicity and inhibit chemoresistance via suppressing Wnt/β-catenin signaling in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a type of cancer characterized by high recurrence rates. Overcoming chemoresistance can reduce HCC recurrence and improve patients' prognosis. This work aimed to identify HCC chemoresistance-associated long non-coding RNA (lncRNA) and find an effective drug targeting the identified lncRNA for ameliorating the chemoresistance. In this investigation, bioinformatics analysis based on The Cancer Genome Atlas revealed a new chemoresistance index and suggested LINC02331 as an HCC chemoresistance and patients' prognosis-associated lncRNA that served as an independent prognostic indicator. Moreover, LINC02331 promoted DNA damage repair, DNA replication, and epithelial-mesenchymal transition as well as attenuated cell cycle arrest and apoptosis through regulating Wnt/β-catenin signaling, thus stimulating HCC resistance to cisplatin cytotoxicity, proliferation, and metastasis. Interestingly, we developed a novel oxidative coupling approach to synthesize a dimeric oxyberberine CT4-1, which exerted superior anti-HCC activities without obvious side effects measured by in vivo mice model and could downregulate LINC02331 mice model and could downregulate LINC02331 to mitigate LINC02331-induced HCC progression by suppressing Wnt/β-catenin signaling. RNA sequencing analyses verified the involvement of CT4-1-affected differential expression genes in dysregulated pathways and processes, including Wnt, DNA damage repair, cell cycle, DNA replication, apoptosis, and cell adhesion molecules. Furthermore, CT4-1 was demonstrated to be an effective cytotoxic drug in ameliorating HCC patients' prognosis with a prediction model constructed based on RNA-sequencing data from CT4-1-treated cancer cells and public cancer database. In summary, HCC chemoresistance-associated LINC02331 independently predicted poor patients' prognosis and enhanced HCC progression by promoting resistance to cisplatin cytotoxicity, proliferation, and metastasis. Targeting LINC02331 by the dimeric oxyberberine CT4-1 that exhibited synergistic cytotoxicity with cisplatin could alleviate HCC progression and improve patients' prognosis. Our study identified LINC02331 as an alternative target and suggested CT4-1 as an effective cytotoxic drug in HCC treatment.