Investigation of the expression of TPX2 in tongue squamous cell carcinoma and its effect on Cal27 cell proliferation and apoptosis

To investigate the expression of targeting protein for xenopus kinesin-like protein2 (TPX2) in tongue squamous cell carcinoma (TSCC) tissues and explore its effect on cell proliferation and apoptosis.

30 cases of TSCC tissues, paired normal tissues were collected in Dongguan People’s Hospital during 2013-2016. The mRNA and protein expression level of TPX2 was determined by qRT-PCR and western blot, respectively and analyzed The correlation of TPX2 expression level and clinic opathological parameters. Cal27 cell was transfected with siRNAs to knockdown the expression of TPX2, then cell proliferation, cell apoptosis and related proteins (cleaved caspase 3 and caspase 3) were detected by MTT assay, flow cytometry and western blot.

TPX2 was highly expressed in (t = 3.254, P = 0.0029) tumor tissues at mRNA level compared to adjacent normal parts. In protein level, TPX2 was highly expressed (66.7%) in tumor tissues, TPX2 expression level of 20 case was higher than the corresponding tissue adjacent to carcinoma (20/30, t = 2.862, P = 2.862), and high expression of TPX2 was related to T staging, lymph node metastasis of tongue cancer. Knockdown TPX2 effectively reduced cell proliferation, increased apoptosis rate (F = 342.9, P < 0.0001) and upregulated the expression of apoptosis-related proteins cleaved caspase 3 (F = 46.98, P = 0.0014) and caspase 3 (F = 33.35, P = 0.0027).

Overexpression of TPX2 was found in TSCC tissues. Silencing of TPX2 might inhibit cell proliferation and promote cell apoptosis. TPX2 could be a new target for gene therapy of TSCC.