ABSTRACT
MicroRNAs (miRNAs) act as critical biological factors in gastric cancer (GC). miR-1285 has been ascertained as a crucial antioncogene in some cancers. However, the effect of miR-1285 in GC and the regulatory mechanism are not clear. In this study, we revealed that miR-1285 expression was significantly reduced in GC. Overexpressing miR-1285 restrained GC cell multiplication and accelerated apoptosis, whereas suppressing miR-1285 facilitated cell growth and restrained apoptosis. The level of miR-1285 was negatively related to the RAB1A level in GC tissue specimens. RAB1A was verified by reporter gene assay as a target of miR-1285. Overexpression of miR-1285 suppressed the RAB1A level, whereas suppression of miR-1285 promoted the level of RAB1A expression. Knockdown of RAB1A resulted in analogical biological effect as that caused by overexpressing miR-1285. Moreover, both miR-1285 overexpression and RAB1A knockdown led to suppression of the mTOR/S6K1 pathway. By contrast, inhibition of miR-1285 promoted the mTOR/S6K1 pathway. In addition, miR-1285 also regulated the Bcl-2/Bax pathway. Taken together, our data indicate that miR-1285 suppresses GC cell multiplication by restraining the mTOR/S6K1 pathway and induces cell apoptosis by regulating the Bcl-2/Bax pathway via modulating RAB1A.
Subject(s)
MicroRNAs , Stomach Neoplasms , Apoptosis/genetics , Cell Line, Tumor , Cell Movement , Cell Proliferation/genetics , Cell Transformation, Neoplastic/genetics , Gene Expression Regulation, Neoplastic , Humans , MicroRNAs/genetics , MicroRNAs/metabolism , Proto-Oncogene Proteins c-bcl-2/genetics , Proto-Oncogene Proteins c-bcl-2/metabolism , Stomach Neoplasms/genetics , Stomach Neoplasms/metabolism , TOR Serine-Threonine Kinases/genetics , bcl-2-Associated X Protein/genetics , bcl-2-Associated X Protein/metabolismABSTRACT
Pancreatic cancer (PCC) is one of the most difficult cancers to treat and the 10th leading cause of cancer-related death in worldwide. Studies have demonstrated that the tetraspanin 1 (Tspan1) is overexpressed in various cancers and may be a potential therapeutic strategy for the treatment of different cancers. However, the possible role of Tspan1 in PCC is still unknown. In the present study, our data revealed that the increased Tspan1 in PCC tissues was associated with the clinicopathological features and survival rate of PCC patient. We also investigated the effects of Tspan1 gene knockdown on the biological behavior of human PCC. The expression of Tspan1 (detected by immunohistochemistry, qRT-PCR and western blot analysis) derived from human PCC tissues and cell lines (AsPC-1 and PANC-1), were significantly elevated compared with those of the control (P<0.05). Transfection with siRNA-targeting Tspan1 significantly decreased proliferation, increased the apoptosis and reduced migration and invasion of AsPC-1 and PANC-1 cells. The present study demonstrated that Tspan1 plays an important role in PCC carcinogenic progression, including migration and invasion. The siRNA targeting of Tspan1 may be a potential therapeutic strategy for the treatment of PCC.
Subject(s)
Carcinogenesis/genetics , Cell Proliferation/genetics , Pancreatic Neoplasms/genetics , Tetraspanins/genetics , Apoptosis/genetics , Cell Line, Tumor , Cell Survival/genetics , Gene Expression Regulation, Neoplastic , Humans , Pancreatic Neoplasms/pathology , RNA, Small Interfering/genetics , Tetraspanins/biosynthesisABSTRACT
BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease and still continues to have the worst prognosis of all gastrointestinal malignancies. Reports have demonstrated that secretory leukocyte protease inhibitor (SLPI) is overexpressed in various cancers and may be a potential therapeutic strategy for the treatment of different cancers. However, the possible role of SLPI in PDAC is still unknown. In the present study, we investigate the effects of SLPI gene knockdown on the biological behavior of human pancreatic cancer cells. The expressions of SLPI were detected, by qRT-PCR and Western blot, in human PDAC tissues as well as AsPC-1, BxPC-3 and PANC-1 cells. After transfection with siRNA targeting to SLPI, SLPI expression was detected by qRT-PCR and Western blot in cells. Cell proliferation and apoptosis were also evaluated by MTT assay and flow cytometry (FCM). The trans-well assays were also employed to explore the effects of SLPI knockdown on the migration and invasion of PDAC cells in vitro. RESULTS: The expressions of SLPI derived from human PDAC and PDAC cell lines were significant higher than those of control groups, respectively (P < 0.05). Regression analysis showed elevated SLPI level was positive correlated with development of PDAC. The siRNA target to SLPI significantly decreased the expressions of SLPI in these PDAC cell lines. Following SLPI-siRNA transduction, the proliferative capacity of the AsPC-1, BxPC-3 and PANC-1 cells was significantly inhibitions, compared to the blank (PDAC-wild type cells) and negative (non-targeting scrambled siRNA transduced PDAC cells) control ones, respectively (P < 0.05). Moreover, SLPI knockdown significantly increased the apoptosis fractions and reduced the migration and invasion of PDAC cells in vitro (P < 0.05). CONCLUSIONS: The present study demonstrated that: i) SLPI played an important role in PDAC progression; ii) SLPI might be an important characteristic of malignant PDAC associated with migration and invasion in vitro; and iii) siRNA targeting to SLPI might be a potential therapeutic strategy for the treatment of PCC.
