Rapamycin enhances the anti-tumor activity of cabozantinib in cMet inhibitor-resistant hepatocellular carcinoma / 医学前沿

Cabozantinib, mainly targeting cMet and vascular endothelial growth factor receptor 2, is the second-line treatment for patients with advanced hepatocellular carcinoma (HCC). However, the lower response rate and resistance limit its enduring clinical benefit. In this study, we found that cMet-low HCC cells showed primary resistance to cMet inhibitors, and the combination of cabozantinib and mammalian target of rapamycin (mTOR) inhibitor, rapamycin, exhibited a synergistic inhibitory effect on the in vitro cell proliferation and in vivo tumor growth of these cells. Mechanically, the combination of rapamycin with cabozantinib resulted in the remarkable inhibition of AKT, extracellular signal-regulated protein kinases, mTOR, and common downstream signal molecules of receptor tyrosine kinases; decreased cyclin D1 expression; and induced cell cycle arrest. Meanwhile, rapamycin enhanced the inhibitory effects of cabozantinib on the migration and tubule formation of human umbilical vascular endothelial cells and human growth factor-induced invasion of cMet inhibitor-resistant HCC cells under hypoxia condition. These effects were further validated in xenograft models. In conclusion, our findings uncover a potential combination therapy of cabozantinib and rapamycin to combat cabozantinib-resistant HCC.

Isolation, culture and identification of hepatocellular carcinoma-associated fibroblast and its effect on the biological function of hepatocellular carcinoma cells / 肿瘤研究与临床

Objective To establish an in vitro isolation and culture system for hepatocellular carcinoma (HCC)-associated fibroblast (CAF) and identify based on its specific markers of CAF. Methods CAF was isolated from the tumor tissue of the HCC patients after hepatectomy, by digesting with collagenase enzyme, centrifugation and resuspension. The morphology of CAF was observed by electron microscopy. Immunofluorescence staining was performed for detecting α-SMA and fibronectin as well as other specific markers such as AFP on the surface of HCC cells and CD31 on the surface of vascular endothelial cells. On the basis of the study, the function work between CAF and HCC cell line Huh7, HepG2 was detected under co-culture system. Meanwhile, CCK-8 was used to observe the effect of CAF on the proliferation of Huh7 and HepG2 cells, and Transwell assay was used to analyze CAF effect on the invasion of Huh7 and HepG2 cells. Results Compared with the other cells, the morphological analysis showed that CAF was more elongated or spindle-shaped. Moreover, the cell size and the nucleus were larger than normal epithelial cells. Immunofluorescence staining revealed that the CAF surface specific markers including α-SMA and fibronectin were positive, and mainly were the cell membrane staining. The proliferation and invasion of Huh7 and HepG2 were significantly increased by CAF. The results show that the increasing percentage of cells in 24 hours between blank group and the experimental group was (63 ± 4) %, (78 ± 5) % and (69 ± 5) %, (81 ± 3) %respectively after co-culture with CAF, the difference was statistically significant (P<0.05). In transwell model, the number of cells in the blank group and the experimental group was (59.4 ± 3.1), (162.9 ± 3.9) and (104.8 ± 2.6), (166.4 ± 4.2), and the difference was also statistically significant (P< 0.05). Conclusion The isolated CAF from HCC enhances the ability of tumor's proliferation and invasion.

Hepatocyte growth factor/c-Met signaling pathway decreases doxorubicin sensitivity in hepatocellular carcinoma in vitro / 肿瘤研究与临床

Objective To explore the effect of hepatocyte growth factor (HGF)/c-Met signaling in doxorubicin (DOX) treatment of hepatocellular carcinoma (HCC). Methods Different biologic and genetic characteristics human HCC cell lines, Huh7, HepG2, MHCC97-L and MHCC97H were used in this experiment. Variation in c-Met mRNA expression level among different HCC cell lines was analyzed by RT-PCR. Western blot analysis was performed to detect c-Met and p-Met expression levels in these cell lines. CCK-8 experiment was carried to analyze the DOX sensitivity in various cell lines. t test and repeated measure analysis of variance were used for statistical analysis. Results Both c-Met and p-Met were overexpressed in MHCC97-L and MHCC97-H cell lines and these cell lines were resistant to DOX compared to Huh7 and HepG2. However, treatment of HGF in Huh7 and HepG2 cells activated c-Met signaling pathway and decreased the sensitivity of these two cell lines to DOX [inhibition rate: Huh7 (34.848 ±5.370) vs. (66.409±5.792)%, HepG2 (34.351±3.305) %vs. (62.308±5.453) %, both P=0.002]. Whereas administration of c-Met inhibitor in MHCC97-L and MHCC97-H cell lines significantly increased the sensitivity to DOX [inhibition rate: MHCC97-L (73.106 ±3.472) % vs. (13.636 ±4.097) %; MHCC97-H (64.444 ±4.006) % vs. (6.296 ±2.796) %, both P< 0.001]. Conclusion HGF/c-Met signaling pathway is related the treatment efficacy of DOX in HCC.

Phenotype and distribution of infiltrating lymphocytes in liver cancer tissues / 中国肿瘤临床

Objective:To identify the signature of tumor-infiltrating lymphocyte (TIL) subtypes that may affect cytokine expres-sion between different outcomes of hepatocellular carcinoma (HCC) patients by analyzing the CD molecular expression profiles of non-cancerous hepatic tissues. Methods:Surface markers of TIL in noncancerous hepatic tissues from 146 HCC patients were determined by using immunohistochemical method and flow cytometry. Univariate and multivariate Cox proportional hazards models and Kaplan-Meier method were used to analyze the association of their expression levels with tumor recurrence and survival. Results:More than 86.4%of TILs in patients were quiescent, as measured via CD4+or Foxp3 expression. Meanwhile, more than 90%of CD3+T cells ex-pressed CD8+. The proportion of T cells was low compared with CD8+T cells. The proportion of CD19 and CD20 in distant nontumor tissues almost was zero. The proportion of T cell subgroups isolated from HCC circulating whole blood did not show a significant shift compared with the normal control, as follows:CD4+T/CD8+T=1.167 ± 1.04, CD8+T/CD3+T=0.288 ± 0.116, and CD4+T/CD3+T=0.429 ± 0.178. The proportion of CD8+T cells in noncancerous hepatic tissues was higher than that in blood (P<0.001).Conclusion:TILs in HCC noncancerous hepatic tissues are increased and contain a subpopulation of CD3+CD8+T cells. CD8+T cells in cancerous tissues, rather than noncancerous tissues, show significant differences between different prognostic groups.