Differential expression of store-operated calcium- and proliferation-related genes in hepatocellular carcinoma cells following TRPC1 ion channel silencing

Abstract

TRPC1 and store-operated Ca2+ (SOC) entry have previously been associated with hepatocellular carcinoma cell proliferation. The aim of the study was to determine genes and processes associated with TRPC1 down-regulation and the resulting increase of SOC entry and decrease in hepatocellular carcinoma cell proliferation. For this purpose, transcriptome analysis was performed to determine differentially expressed genes in TRPC1-silenced Huh7 cells. SOC entry- and proliferation-related genes correlated with TRPC1 down-regulation were also examined. Changes in SOC entry and cell proliferation were monitored in the TRPC1-silenced and parental cells and found to be significantly increased and decreased, respectively, in TRPC1-silenced cells. A total of 71 genes were significantly differentially expressed (40 up- and 31 down-regulated), including four mitogen-activated protein kinase (MAPK) signalling-associated genes. STIM1 levels were significantly up-regulated and negatively correlated with TRPC1 levels. In addition, expression of two cell cycle regulation genes, CDK11A/11B and URGCP, was observed to decrease, whereas ERBB3 and FGFR4, pro-survival genes, increased significantly in TRPC1-silenced cells. In conclusion, these results suggest reciprocal alterations in TRPC1 and STIM1 levels and a role for STIM1 in the regulation of SOC entry in TRPC1-silenced Huh7 cells. In addition to TRPC1, STIM1 may participate in Huh7 cell proliferation by regulating SOC entry. Alterations in MAPK signalling genes may be involved in diminished cell proliferation in TRPC1-silenced Huh7 cells. Similarly, changes in cell cycle regulating genes in TRPC1-silenced cells indicate possible cell cycle arrest along with compensatory up-regulation of ERBB3 growth factor receptor—amongst others—to maintain hepatocellular carcinoma cell proliferation.

Inhibition of Orai1‐mediated Ca2+ entry enhances chemosensitivity of HepG2 hepatocarcinoma cells to 5‐fluorouracil

“…Previous work in HCC‐LM3 hepatoma cells showed that blockade of STIM‐mediated SOCE decreased the focal adhesion turnover and thus inhibited cell migration . Furthermore, silencing of TRPC1 was associated with inhibition of hepatocarcinoma cell proliferation by causing cell cycle arrest . These results suggest SOCs play a critical role in regulating chemoresistance of hepatocarcinoma cells.…”

“…Recently, an increase in SOCE, related to the up‐regulation of Stim1, Orai1 or TRPC1 expressions, has been observed in several different kinds of tumours , indicating SOCs are the potential therapeutic target for treatment of cancers. In hepatocarcinoma, recent studies have shown that inhibition of TRPC1 inhibits cell proliferation by regulating SOCE . Moreover, Stim1 expression is found to increase in hepatoma tissues than in precancerous tissues, and blockade of Stim1‐mediated SOCs inhibits migration and invasion of hepatocarcinoma cells .…”

“…Upon ER store depletion, STIM1 aggregates and translocates to plasma membrane and then interacts directly with Orai1 and/or TRPC1 to form open SOCs that cause SOCE . Interestingly, the three constituents of SOCE, Stim1, Orai1 and TRPC1, have been detected in liver cells and associated with the initiation and progression of liver cancer . Previous work in HCC‐LM3 hepatoma cells showed that blockade of STIM‐mediated SOCE decreased the focal adhesion turnover and thus inhibited cell migration .…”

Development of an immune-related prognostic index associated with hepatocellular carcinoma

“…Researchers have gained an insight into the tumor-linked infiltrated inflammatory environments, nonetheless, numerous aspects of LIHC immuneassociated molecular mechanisms remain unclear, and the biomarkers for predicting the treatment response are still lacking. A body of studies have uncovered the DEGs between LIHC and non-tumor samples [18][19][20], which contributes to the fundamental understanding towards the pathogenesis of LIHC at genetic level. For example, Carone et al detected the expression levels of 579 immune response-related genes in 30 frozen LIHC liver tissue samples and 33 normal tissues, and demonstrated that the longer time to LIHC recurrence (TTR) was associated with up-regulation of immune response-and inflammation-related genes in tumor tissues, whereas down-regulation of these genes in normal tissues [21].…”

Targeting Ca2+ Signaling in the Initiation, Promotion and Progression of Hepatocellular Carcinoma

“…Studies with TRPC1 have provided indirect evidence for a role for store-operated Ca 2+ entry in the mechanisms by which cell proliferation is enhanced in HCC cells [ 96 , 97 ]. From the results of studies employing the Huh-7 HCC cell line and shRNA to suppress TRPC1 expression, the authors suggested possible roles for both store-operated Ca 2+ entry and TRPC1 in the regulation of cell proliferation in HCC cells.…”