Overexpression of insulin-like growth factor-Ⅰ receptor as a pertinent biomarker for hepatocytes malignant transformation

AIM:To investigate the dynamic features of insulinlike growth factor-Ⅰreceptor(IGF-ⅠR)expression in rat hepatocarcinogenesis,and the relationship between IGF-ⅠR and hepatocytes malignant transformation at mRNA or protein level.METHODS:Hepatoma models were made by inducing with 2-fluorenylacetamide(2-FAA)on male SpragueDawley rats.Morphological changes of hepatocytes were observed by pathological Hematoxylin and eosin staining,the dynamic expressions of liver and serum IGF-ⅠR were quantitatively analyzed by an enzymelinked immunosorbent assay.The distribution of hepatic IGF-ⅠR was located by immunohistochemistry.The fragments of IGF-ⅠR gene were amplified by reverse transcription-polymerase chain reaction,and confirmed by sequencing.RESULTS:Rat hepatocytes after induced by 2-FAA were changed dynamically from granule-like degeneration,precancerous to hepatoma formation with the progressing increasing of hepatic mRNA or IGF-ⅠR expression.The incidences of liver IGF-ⅠR,IGF-ⅠR mRNA,specific IGF-ⅠR concentration(ng/mg wet liver),and serum IGF-ⅠR level(ng/mL)were 0.0%,0.0%,0.63±0.17,and 1.33±0.47 in the control;50.0%,61.1%,0.65±0.2,and 1.51±0.46 in the degeneration;88.9%,100%,0.66±0.14,and 1.92±0.29 in the precancerosis;and 100%,100%,0.96±0.09,and2.43±0.57 in the cancerous group,respectively.IGF-ⅠR expression in the cancerous group was significantly higher(P<0.01)than that in any of other groups at mRNA or protein level.The closely positive IGF-ⅠR relationship was found between livers and sera(r=0.91,t=14.222,P<0.01),respectively.CONCLUSION:IGF-ⅠR expression may participate in rat hepatocarcinogenesis and its abnormality should be an early marker for hepatocytes malignant transformation.

Annexin A2 silencing inhibits invasion, migration, and tumorigenic potential of hepatoma cells

AIM: To investigate the effects of Annexin A2 (ANXA2) silencing on invasion, migration, and tumorigenic potential of hepatoma cells. METHODS: Human hepatoma cell lines [HepG2, SMMC-7721, SMMC-7402, and MHCC97-H, a novel human hepatocellular carcinoma (HCC) cell line with high metastasis potential] and a normal hepatocyte cell line(LO2) were used in this study. The protein and mRNA expression levels of ANXA2 were analysed by western blotting and real-time polymerase chain reaction, re-spectively. The intracellular distribution profile of ANXA2 expression was determined by immunofluorescence and immunohistochemistry. Short hairpin RNA target-ing ANXA2 was designed and stably transfected into MHCC97-H cells. Cells were cultured for in vitro analy-ses or subcutaneously injected as xenografts in mice for in vivo analyses. Effects of ANXA2 silencing on cell growth were assessed by cell counting kit-8 (CCK-8) as-say (in vitro ) and tumour-growth assay (in vivo ), on cell cycling was assessed by flow cytometry and propidium iodide staining (in vitro ), and on invasion and migration potential were assessed by transwell assay and wound-healing assay, respectively (both in vitro ). RESULTS: The MHCC97-H cells, which are known to have high metastasis potential, showed the highest lev-el of ANXA2 expression among the four HCC cell types examined; compared to the LO2 cells, the MHCC97-H expression level was 8-times higher. The ANXA2 expres-sion was effectively inhibited (about 80%) by ANXA2-specific small hairpin RNA (shRNA). ANXA2 expression in the MHCC97-H cells was mainly localized to the cel-lular membrane and cytoplasm, and some localization was detected in the nucleus. Moreover, the proliferation of MHCC97-H cells was obviously suppressed by shR-NA-mediated ANXA2 silencing in vitro , and the tumour growth inhibition rate was 38.24% in vivo . The per-centage of MHCC97-H cells in S phase dramatically de-creased (to 27.76%) under ANXA2-silenced conditions. Furthermore, ANXA2-silenced MHCC97-H cells showed lower invasiveness (percentage of invading cells de-creased to 52.16%) and suppressed migratory capacity (migration distance decreased to 63.49%). It is also worth noting that shRNA-mediated silencing of ANXA2 in the MHCC97-H cells led to abnormal apoptosis. CONCLUSION: shRNA-mediated silencing of ANXA2suppresses the invasion, migration, and tumorigenic potential of hepatoma cells, and may represent a useful target of future molecular therapies.