Soluble purified recombinant C2ORF40 protein inhibits tumor cell growth in vivo by decreasing telomerase activity in esophageal squamous cell carcinoma

Abstract

Abstract.The chromosome 2 open reading frame 40 (C2ORF40) gene is a candidate tumor suppressor gene for a variety of tumors. Previous results by the present authors revealed that the C2ORF40 protein is a secreted protein.However, the exact biological function of secreted C2ORF40 protein in carcinogenesis has not been thoroughly investigated. In the present study, the signal peptide sequence of the C2ORF40 cDNA was initially removed to produce secreted recombinant human C2ORF40 protein (rhC2ORF40). Soluble rhC2ORF40 was successfully expressed and purified, which was evaluated for the first time, to the best of our knowledge, for tumor-suppressing function in vivo in esophageal cancer. The present results revealed that soluble purified rhC2ORF40 was concentrated with a purity of >95%. Furthermore, rhC2ORF40 inhibited esophageal cancer cell growth in vivo in a dose-dependent manner compared with a control group (P<0.05). In addition, the present study demonstrated for the first time that rhC2ORF40 decreased telomerase activity using telomeric repeat amplification protocol-enzyme-linked immunosorbent assay (P<0.05), without affecting the expression levels of telomerase-component RNA (P>0.05), as shown with polymerase chain reaction. Overall, the present results demonstrated that soluble rhC2ORF40 inhibited tumor cell growth in vivo by decreasing telomerase activity in esophageal squamous cell carcinoma. Therefore, soluble rhC2ORF40 with a high purity and biological activity may be a potential biological therapy drug for esophageal cancer.

Identification of Differentially Expressed Genes Induced by Aberrant Methylation in Oral Squamous Cell Carcinomas Using Integrated Bioinformatic Analysis

“…The four downregulated hypermethylated TSGs were C2orf40 , EPB41L3 , GPX3 , and WIF1 . C2orf40 (chromosome 2 open reading frame 40) is a protein-coding gene, associated with diseases such as esophageal cancer [ 32 ]. It functions as a probable hormone that induces senescence of oligodendrocyte and neural precursor cells, characterized by G1 arrest, RB1 dephosphorylation, and accelerated CCND1 and CCND3 proteasomal degradation [ 33 ].…”

Comprehensive pan‐cancer analysis of the C2ORF40 expression: Infiltration associations and prognostic implications

“…It is expressed in a variety of normal tissues including esophageal, heart, brain, placenta, lung, liver, kidney, and pancreas et al This gene plays roles in maintaining cerebrospinal fluid homeostasis, stimulating neural precursor cells after brain injury, and inducing senescence of central nervous system cells. [5][6][7] C2ORF40 encodes a protein with a hydrophobic leader sequence. This sequence is cleaved into smaller peptide segments by protein convertases or thrombin, a process believed to be essential for C2ORF40 to have cell type-specific biological activity.…”

“…It is expressed in a variety of normal tissues including esophageal, heart, brain, placenta, lung, liver, kidney, and pancreas et al. This gene plays roles in maintaining cerebrospinal fluid homeostasis, stimulating neural precursor cells after brain injury, and inducing senescence of central nervous system cells 5–7 . C2ORF40 encodes a protein with a hydrophobic leader sequence.…”

“…This sequence is cleaved into smaller peptide segments by protein convertases or thrombin, a process believed to be essential for C2ORF40 to have cell type‐specific biological activity 8 . Notably, C2ORF40 expression is dramatically lower in multiple cancers, including esophageal, 5 prostate, 9 , and breast cancers 10 . Li et al.…”

“…This sequence is cleaved into smaller peptide segments by protein convertases or thrombin, a process believed to be essential for C2ORF40 to have cell type-specific biological activity. 8 Notably, C2ORF40 expression is dramatically lower in multiple cancers, including esophageal, 5 prostate, 9 , and breast cancers. 10 Li et al demonstrated that using the mimic peptide fragment (C2ORF40MPF) of a synthetic human, C2ORF40MPF can inhibit breast cancer cell proliferation and migration in vitro, induce G2/M phase cell cycle arrest, and decrease tumor incidence in xenograft models.…”