RESUMO
UNLABELLED: Early reports suggested that actopaxin, a member of the focal adhesion proteins, regulates cell migration. Here we investigated whether actopaxin is involved in hepatocellular carcinoma (HCC) progression and metastasis. We examined actopaxin expression in human HCC samples using immunohistochemistry and western blotting. The functional and molecular effect of actopaxin was studied in vitro by overexpression in a nonmetastatic HCC cell line, as well as repression in a metastatic cell line. The in vivo effect of actopaxin repression was studied in nonobese diabetic and severe combined immunodeficient mice. We found that actopaxin was frequently overexpressed in human HCC patients and its overexpression positively correlated with tumor size, stage, and metastasis. Actopaxin expression also correlated with the metastatic potential of HCC cell lines. Actopaxin overexpression induced the invasion and migration ability of nonmetastatic HCC cells, whereas down-regulation of actopaxin reverted the invasive phenotypes and metastatic potential of metastatic HCC cells through regulating the protein expression of certain focal adhesion proteins including ILK, PINCH, paxillin, and cdc42, as well as regulating the epithelial-mesenchymal transition pathway. Furthermore, there was a close association between actopaxin and CD29. HCC cells with stronger CD29 expression showed a higher actopaxin level, whereas actopaxin repression attenuated CD29 activity. Finally, actopaxin down-regulation enhanced the chemosensitivity of HCC cells towards oxaliplatin treatment by way of a collective result of suppression of survivin protein, ß-catenin, and mammalian target of rapamycin pathways and up-regulation of p53. CONCLUSION: This study provides concrete evidence of a significant role of actopaxin in HCC progression and metastasis, by way of regulation of cell invasiveness and motility, an epithelial-mesenchymal transition process, and chemosensitivity to cytotoxic drugs.
Assuntos
Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/fisiopatologia , Movimento Celular/fisiologia , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/fisiopatologia , Proteínas dos Microfilamentos/antagonistas & inibidores , Metástase Neoplásica/fisiopatologia , Animais , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Carcinoma Hepatocelular/mortalidade , Linhagem Celular Tumoral , Células Cultivadas , Modelos Animais de Doenças , Progressão da Doença , Transição Epitelial-Mesenquimal/fisiologia , Feminino , Xenoenxertos , Humanos , Técnicas In Vitro , Integrina beta1/fisiologia , Neoplasias Hepáticas/mortalidade , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Proteínas dos Microfilamentos/efeitos dos fármacos , Proteínas dos Microfilamentos/fisiologia , Pessoa de Meia-Idade , Invasividade Neoplásica/patologia , Invasividade Neoplásica/fisiopatologia , Metástase Neoplásica/patologia , Compostos Organoplatínicos/farmacologia , Oxaliplatina , RNA Interferente Pequeno/farmacologia , Taxa de SobrevidaRESUMO
Introduction: Immunotherapy has resulted in pathologic responses in hepatocellular carcinoma (HCC), but the benefits and molecular mechanisms of neoadjuvant immune checkpoint blockade are largely unknown. Methods: In this study, we evaluated the efficacy and safety of preoperative nivolumab (anti-PD-1) in patients with intermediate and locally advanced HCC and determined the molecular markers for predicting treatment response. Results: Between July 2020 and November 2021, 20 treatment-naive HCC patients with intermediate and locally advanced tumors received preoperative nivolumab at 3 mg/kg for 3 cycles prior to surgical resection. Nineteen patients underwent surgical resection on trial. Seven (36.8%) of the 19 patients had major pathologic tumor necrosis (≥60%) in the post-nivolumab resection specimens, with 3 having almost complete (>90%) tumor necrosis. The tumor necrosis was hemorrhagic and often accompanied by increased or dense immune cell infiltrate at the border of the tumors. None of the patients developed major adverse reactions contradicting hepatectomy. RNA-sequencing analysis on both pre-nivolumab tumor biopsies and post-nivolumab resected specimens showed that, in cases with major pathologic necrosis, the proportion of CD8 T cells in the HCC tissues predominantly increased after treatment. Moreover, to investigate noninvasive biomarker for nivolumab response, we evaluated the copy number variation (CNV) using target-panel sequencing on plasma cell-free DNA of the patients and derived a CNV-based anti-PD-1 score. The score correlated with the extent of tumor necrosis and was validated in a Korean patient cohort with anti-PD-1 treatment. Conclusion: Neoadjuvant nivolumab demonstrated promising clinical activity in intermediate and locally advanced HCC patients. We also identified useful noninvasive biomarker predicting responsiveness.