HOXA10 enhances cell proliferation and suppresses apoptosis in esophageal cancer via activating p38/ERK signaling pathway

Abstract

Esophageal cancer (EC) is an extremely aggressive malignant tumor. Homeobox A10 (HOXA10) is highly expressed and plays an important role in a variety of tumors. However, the function of HOXA10 in EC remains unclear. In this study, HOXA10 was observed to highly express in EC tissues and cells. Interestingly, the CCK-8 assay, flow cytometry, and colony formation assay confirmed that overexpression of HOXA10 promoted proliferation and suppressed cell apoptosis in EC cells. More importantly, the western blot assay indicated that the phosphorylation levels of ERK and p38 were elevated in EC cells overexpressed HOXA10, indicating that overexpression of HOXA10 activated p38/ERK signaling pathway in EC cells. These findings concluded that HOXA10 aggravated EC progression via activating p38/ERK signaling pathway, providing a potential therapeutic target for EC.

Keywords: ERK signaling pathway; HOXA10; apoptosis; esophageal cancer; p38 signaling pathway; proliferation.

Figure 1

HOXA10 was highly expressed in EC tissues and cells. (a) The HOXA10 expression was elevated in primary tumor tissues, which was analyzed by TCGA (a), GEPIA (a′), and UCSC Xena (a″) databases. (b) The HOXA10 mRNA level was increased in EC cell lines containing Eca-109, EC9706, TE-1, and KYSE150. (c) The HOXA10 protein level was promoted in EC cell lines. Each experiment repeated three times. ^* p  < 0 .05, ^** p  <  0.01, ^*** p  <  0.001.

Figure 2

Overexpression of HOXA10 enhanced proliferation in EC cells. (a) Real-time PCR showed HOXA10 mRNA level in Eca-109 and TE-1 cells. (b) Western blot showed HOXA10 protein level in Eca-109 and TE-1 cells. (c) CCK-8 assay revealed that the elevation of cell viability was caused by HOXA10 overexpression and inhibition of cell viability was induced by HOXA10 knockdown. (d) Clone formation assay determined that HOXA10 overexpression increased the colony number and HOXA10 knockdown suppressed the colony number. Each experiment repeated three times. ^** p  <  0.01, ^*** p  < 0 .001 vs NC. ^@@ p < 0.01, ^@@@ p < 0.001 vs siNC.

Figure 3

Overexpression of HOXA10 suppressed cell apoptosis in EC cells. (a) The siHOXA10 increased apoptosis rate of Eca-109 and TE-1 cells and overexpression of HOXA10 increased apoptosis rate. Annexin V-FITC assay was used to measure cell apoptosis. (b) The apoptosis-related proteins containing Bax, Bcl-2, cleaved caspase-3, and cleaved caspase-9 were determined by western blot Eca-109 and TE-1 cells. (c) The cleaved PARP and PARP protein levels were assessed by western blot. Each experiment repeated three times. ^* p  <  0.05, ^** p  <  0.01, ^*** p  < 0 .001 vs NC. ^@ p < 0.05, ^@@ p < 0.01, ^@@@ p < 0.001 vs siNC.

Figure 4

HOXA10 activated p38/ERK signaling pathway in EC cells. After transfected with oe-HOXA10 or siHOXA10, the p-ERK, ERK, p-P38, and P38 expressions were detected by western blot in Eca-109 and TE-1 cells. Each experiment repeated three times. ^*** p  < 0 .001 vs NC. ^@ p < 0.05, ^@@ p < 0.01, ^@@@ p < 0.001 vs siNC.

Figure A1

Knockdown of HOXA10 reduced cell proliferation and enhanced apoptosis in EC cells. (a) The western blot showed HOXA10 expression in Eca-109 cells. (b) The cell viability in Eca-109 cells was determined by CCK-8 assay. (c) The cell apoptosis in Eca-109 cells was detected by Annexin V-FITC assay.