Elevated expression of RAB3B plays important roles in chemoresistance and metastatic potential of hepatoma cells

Abstract

Background Cancer stem cells (CSCs) are thought to play important roles in carcinogenesis, recurrence, metastasis, and therapy-resistance. We have successfully induced cancer stem-like sphere cells (CSLCs) which possess enhanced chemoresistance and metastatic potential. To enable the development of targeted therapy against CSLCs, we identified a gene responsible for this phenotype in CSLC. Methods Human hepatoma cell line SK-HEP-1 was used for CSLC induction with a unique sphere inducing medium, and HuH-7 cells were used as non-sphere forming cells in the same condition. RNA-sequencing was performed followed by validation with quantitative RT-PCR and western blotting. Knockdown experiments were done by using CRISPR-Cas9 genome-editing, and the rescue experiments were performed using the expressing plasmid vector. Chemoresistance and liver metastasis of the cells, was studied following the splenic injection of cells to severely immune deficient mice and evaluated using the MTS assay. Quantification of exosomes in the medium was done using ELISA. Results RAB3B was identified as an up-regulated gene in both CSLCs and prognostically poor hepatocellular carcinoma (HCC) by RNA-sequencing. RAB3B-KD cells showed altered CSLC phenotypes such as sphere formation, chemoresistance, and metastatic potentials, and those were rescued by RAB3B complementation. Increased exosome secretion was observed in CSLCs, and it was not observed in the RAB3B-KD cells. In addition, the RAB3B expression correlated with the expression of ABCG2, APOE, LEPR, LXN, and TSPAN13. Conclusion The up regulation of RAB3B may play an important role in the chemoresistance and metastatic potential of CSLCs.

Raltitrexed enhanced antitumor effect of anlotinib in human esophageal squamous carcinoma cells on proliferation, invasiveness, and apoptosis

“…The in vitro cytotoxicity were measured by MTS (Vicmed, Xuzhou, Jiangsu, China) assay [ 18 ]. Briefly, cells were seeded in 96-well plates at a density of 4 × 10 3 cells/well at 37 °C overnight.…”

Expression of Chemoresistance-Associated ABC Proteins in Hepatobiliary, Pancreatic and Gastrointestinal Cancers

“…ABCG2 expression is typically very high in the so-called side-population (SP) of stem cells, whose chemoresistance is stronger than those without stemness characteristics [ 51 ]. Thus, BCRP is a potential marker for liver cancer stem cells (LCSC) [ 52 , 53 ]. Interestingly, BCRP expression is closely related to the initiation, proliferation, metastasis, and chemoresistance of HCC.…”

“…ABCG2 expression, which can be modulated by AKT signaling, can significantly influence the efflux from HCC cells of drugs such as doxorubicin, therefore hindering their efficacy [ 54 ]. In addition, the development in HCC cells of an LCSC phenotype, in which ABCG2 upregulation is prominent, is associated with malignant traits, such as increased proliferation, migration, and invasion [ 53 ]. It is noteworthy that these features can be diminished by ABCG2 downregulation [ 52 ].…”

Female Germ Cell Development in Chickens and Humans: The Chicken Oocyte Enriched Genes Convergent and Divergent with the Human Oocyte

“…RAB3B is one of the members of the Rab family. It exhibits GTPase activities and acts as a central regulator of vesicular traffic [ 111 , 112 ]. RAB3B expression has been associated with several cancer cells, where the silencing of RAB3B significantly inhibits cell proliferation and promotes apoptosis [ 112 , 113 ].…”

“…It exhibits GTPase activities and acts as a central regulator of vesicular traffic [ 111 , 112 ]. RAB3B expression has been associated with several cancer cells, where the silencing of RAB3B significantly inhibits cell proliferation and promotes apoptosis [ 112 , 113 ]. GSTO2 was detected ubiquitously; however, it was localized in the cytoplasm only or both the cytoplasm and the nucleus in a cell-specific manner.…”