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

Relevance of transportome among the mechanisms of chemoresistance in hepatoblastoma

Approximately 20 % of hepatoblastomas (HBs) exhibit a poor response to conventional chemotherapy due to mechanisms of chemoresistance (MOCs), such as reduced intracellular drug accumulation. This study evaluated the role of transportome in the multidrug resistance (MDR) of HB. Paired HB and adjacent liver tissue samples (n = 19) and HB-derived cell lines (HepG2, HuH6) were analyzed for their resistome characterization at mRNA (RT-qPCR, Taqman Low-Density Array, sequencing) and protein (western blot, immunohistochemistry, immunofluorescence) levels. Cell viability (MTT test) proliferation and migration (holographic microscopy) were determined. The impact of short-term (72 h) and long-term (>10 months) exposure of HB cells to cisplatin or doxorubicin on the transportome was investigated. Solute carrier (SLC) family of transporters showed minor relevance in HB MDR, while drug export pumps, particularly MRP2, were associated with poor response to chemotherapy. Exposure of HB cells to doxorubicin or cisplatin up-regulated MDR1, MRP1 and MRP2. In cells with induced persistent chemoresistance, the expression of genes involved in other MOCs, and epigenetic machinery was altered. Chemoresistant cells showed cross-resistance to several anticancer drugs but maintained sensitivity to cabozantinib. In conclusion, drug export pumps, but not SLC uptake transporters, are key contributors to HB chemoresistance. Cabozantinib emerges as a potential therapeutic option for HBs resistant to conventional chemotherapy.

Molecular and pathological landscape of the AT-rich interaction domain 1A (ARID1A) mutation in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths worldwide, with complex etiological factors and a diverse genetic landscape. Among the critical genetic mutations in HCC, the AT-rich interaction domain 1 A (ARID1A) gene, a key component of the SWI/SNF chromatin remodeling complex, stands out due to its significant role in both tumor suppression and oncogenesis. This review comprehensively examines the molecular and pathological impacts of ARID1A mutations in HCC. ARID1A mutations, which occur in approximately 7.9 % of HCC cases, predominantly involve truncating mutations leading to loss of function. These mutations are associated with various aggressive cancer features, including larger tumor size, higher rates of metastasis, and poor prognosis. The dual role of ARID1A in HCC is context-dependent, acting as a tumor suppressor by regulating cell cycle control, DNA damage repair, and gene expression, while also displaying oncogenic properties in specific contexts by promoting early tumorigenesis through oxidative stress pathways. Understanding the molecular mechanisms of ARID1A, including its interactions with key cellular pathways such as PI3K/AKT/mTOR, β-catenin, and PD-L1, provides insights into its complex role in HCC pathogenesis. Furthermore, ARID1A's impact on cancer stem cell maintenance, metabolic reprogramming, and immune evasion underscores its potential as a therapeutic target. This review highlights the need for context-specific therapeutic strategies targeting ARID1A, which could lead to more effective treatments for HCC, addressing both its tumor-suppressive and oncogenic activities.

Sensitizing cholangiocarcinoma to chemotherapy by inhibition of the drug-export pump MRP3

AIMS

Drug export through ABC proteins hinders cancer response to chemotherapy. Here, we have evaluated the relevance of MRP3 (ABCC3) in cholangiocarcinoma (CCA) as a potential target to overcome drug resistance.

METHODS

Gene expression was analyzed in silico using the TCGA-CHOL database and experimentally (mRNA and protein) in resected CCA tumors. The effect of manipulating MRP3 function/expression was evaluated in vitro and in vivo.

RESULTS

High MRP3 expression at the plasma membrane of human CCA cells was found. MRP3 overexpression in HEK293T cells selectively impaired the cytotoxic effect of etoposide, cisplatin, SN-38, and mitoxantrone. Reduced MRP3 activity with shRNAs or pan-MRP blockers enhanced the sensitivity to these drugs. MRP3 interaction with natural and semisynthetic compounds (≈40,000) was evaluated by virtual drug screening and molecular docking. Two identified potential MRP3 inhibitors (EM-114, EM-188), and sorafenib impaired MRP3 transport activity and enhanced sensitivity of CCA cells to etoposide and cisplatin. The antitumor effect of cisplatin in the mouse xenograft model was enhanced by co-treatment with sorafenib, which was accompanied by a higher intratumor accumulation of cisplatin.

CONCLUSIONS

Genetic and pharmacological MRP3 inhibition enhances the anti-CCA effect of several drugs, which constitutes a promising strategy to improve the response to chemotherapy in CCA patients.

Advances in hepatocellular carcinoma drug resistance models

Hepatocellular carcinoma (HCC) is the most common primary liver cancer. Surgery has been the major treatment method for HCC owing to HCC's poor sensitivity to radiotherapy and chemotherapy. However, its effectiveness is limited by postoperative tumour recurrence and metastasis. Systemic therapy is applied to eliminate postoperative residual tumour cells and improve the survival of patients with advanced HCC. Recently, the emergence of various novel targeted and immunotherapeutic drugs has significantly improved the prognosis of advanced HCC. However, targeted and immunological therapies may not always produce complete and long-lasting anti-tumour responses because of tumour heterogeneity and drug resistance. Traditional and patient-derived cell lines or animal models are used to investigate the drug resistance mechanisms of HCC and identify drugs that could reverse the resistance. This study comprehensively reviewed the established methods and applications of in-vivo and in-vitro HCC drug resistance models to further understand the resistance mechanisms in HCC treatment and provide a model basis for possible individualised therapy.

Breaking the Barriers of Therapy Resistance: Harnessing Ferroptosis for Effective Hepatocellular Carcinoma Therapy

Ferroptosis is a type of cell death that relies on iron and is distinguished by the occurrence of lipid peroxidation and the buildup of reactive oxygen species. Ferroptosis has been demonstrated to have a significant impact on the advancement and resistance to treatment of hepatocellular carcinoma (HCC), thereby highlighting its potential as a viable therapeutic target. Ferroptosis was observed in HCC tissues in contrast to normal liver tissue. The inhibition of ferroptosis has been found to increase the viability of HCC cells and decrease their susceptibility to various anticancer therapies, including chemotherapy, radiotherapy, and immune checkpoint blockade. The administration of drugs that directly modulate ferroptosis regulators or induce excessive production of lipid-reactive oxygen species has demonstrated the potential to enhance the responsiveness of drug-resistant HCC cells to treatment. However, the precise mechanism underlying this phenomenon remains ambiguous. This review presents a comprehensive overview of the crucial role played by ferroptosis in enhancing the efficacy of treatment for hepatocellular carcinoma (HCC). The main aim of this study is to examine the feasibility of utilizing ferroptosis as a therapeutic approach to improve the efficacy of HCC treatment and overcome drug resistance.

SIVA-1 enhances acquired chemotherapeutic drug resistance of gastric cancer in vivo by regulating the ARF/MDM2/p53 pathway

SIVA-1 has been shown to affect apoptotic processes in various different cell lines, and SIVA-1 significantly contributes to the decreased responsiveness of cancer cells to some chemotherapy agents. However, whether SIVA-1 has potential application in gastric cancer remains unknown. Therefore, the objective of this investigation was to clarify the distinct function of SIVA-1 in chemotherapeutic drug resistance within a living murine model with gastric malignancy, and initially elucidate the underlying mechanisms. In an established multidrug-resistant gastric cancer xenograft mouse model, lentivirus, named Lv-SIVA-1, was injected into xenograft tumors, and increased the mRNA and protein expression of endogenous SIVA-1 in tumors. Immunohistochemical assays of xenograft tumor showed that SIVA-1 was significantly upregulated, and the protein expression levels of SIVA-1 were highly increased, as detected by Western blotting. In addition, we detected the role of SIVA-1 in cell proliferation and cell apoptosis in gastric cancer cells by TUNEL and found that SIVA-1 decreased tumor cell apoptosis and promoted tumor growth in vivo. Using a TMT assay between tumor tissues of experimental and control groups, differentially expressed proteins were examined and three potential biomarkers of multidrug resistance (ARF, MDM2, and p53) were screened. We further investigated the molecular mechanism by which SIVA-1 played an efficient role against chemotherapies and found that overexpressed SIVA-1 leads to increased ARF and MDM2 expression and suppressed expression of p53 in tumor tissue. In conclusion, SIVA-1 plays a significant role in the multidrug resistance of gastric tumors. In addition, overexpressed SIVA-1 positively regulates cell proliferation, adjusts cycle progression, and reduces the response to drug treatment for gastric cancer in an ARF/MDM2/p53-dependent manner. This novel research provides a basis for chemical management of gastric cancer through regulation of SIVA-1 expression.