Programmed cell death 1 expression in esophageal squamous cell carcinoma and association with clinical characteristics

OBJECTIVE

The aim of this retrospective study was to evaluate the programmed cell death 1 (PD-1) expression in esophageal squamous cell carcinoma (ESCC) and association with clinical characteristics.

MATERIALS AND METHODS

From January 2009 to December 2014, 88 patients with ESCC were retrospectively included in this study. Eighty-eight cancer tissues, 35 paraneoplastic atypical hyperplasia tissues (PAHTs), and 30 relative normal esophageal tissues (RNETs) were collected and tested for expression of PD-1 by immunohistochemistry assay. The PD-1 expression and clinical characteristics of the ESCC patients were evaluated. The prognosis of the ESCC patients was compared between the PD-1 positive and negative patients.

RESULTS

The PD-1 positive rate was 51.2% (45/88), 22.9% (8/35), and 6.7% (2/30) for the cancer tissue, PAHT, and RNET, respectively, with statistical difference (P < 0.05); The PD-1 expression was significantly associated with lymph node metastasis (P < 0.05) and pathology grade (P < 0.05). The median overall survival was 29.8 months and 32.1 months for the PD-1 positive and negative groups without statistical difference (hazard ratio = 1.00, 95% confidence interval = 0.58-1.71, P < 0.05).

CONCLUSION

PD-1 may play a key role in the process of carcinogenesis of ESCC but not associated with prognosis and overall survival.

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

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.

Beclin 1 promotes apoptosis and decreases invasion by upregulating the expression of ECRG4 in A549 human lung adenocarcinoma cells

Although Beclin 1 has been demonstrated to exert an important role in cell autophagy during carcinogenesis, its biological function in lung cancer has yet to be fully elucidated. A previous study by our laboratory identified that knockdown of Beclin 1 promoted cell growth and inhibited apoptosis in the A549 lung cancer cell line. In the present study, a Beclin 1 lentiviral expression vector was constructed, and an A549 cell line was established with a steady expression of Beclin 1. Furthermore, the effect of Beclin 1 overexpression on cell invasion and apoptosis, changes in the activities of the apoptosis‑associated caspases‑3 and ‑9, and the overexpression of esophageal cancer‑related gene 4 (ECRG4) were examined. The results demonstrated that the overexpression of Beclin 1 in A549 cells reduced cell invasion by Matrigel invasion assay and promoted apoptosis by flow cytometric analysis (P<0.01) compared with Lenex‑packaged lentiviral particles and non‑transfected control groups. Furthermore, the overexpression of Beclin 1 in A549 cells increased the activities of caspases‑3 and ‑9 and the expression of ECRG4 (P<0.01) compared with Lenex‑packaged lentiviral particles and non‑transfected control groups. In conclusion, the overexpression of Beclin 1 promoted apoptosis and decreased invasion by upregulating the expression of ECRG4 in A549 lung adenocarcinoma cells. Therefore, the selection of Beclin l as a target for gene therapy represents a more effective method for the treatment of lung cancer.

Soluble purified recombinant C2ORF40 protein inhibits esophageal cancer cell proliferation by inducing cell cycle G1 phase block

Chromosome 2 open reading frame 40 (C2ORF40) plays a significant role in numerous processes, including cell differentiation, senescence, apoptosis, inflammation and neuroendocrine hormone regulation. Moreover, C2ORF40 is a candidate tumor suppressor gene in a variety of tumors, and is closely associated with prognosis. Bioinformatics analysis has indicated that pro-C2ORF40 is a secreted protein with a signal peptide. Secreted C2ORF40 protein (sC2ORF40) exists in cancer cell medium. However, thus far, the exact biological function of sC2ORF40 in carcinogenesis has not been thoroughly researched. In the present study, the signal peptide sequence of the C2ORF40 complementary DNA was initially cut off to produce secreted recombinant human C2ORF40 protein (rhC2ORF40). The soluble rhC2ORF40 was expressed, purified and examined for tumor-suppressing function for the first time. The results revealed that the soluble purified rhC2ORF40 protein was concentrated with a purity of >95%. Furthermore, the rhC2ORF40 inhibited esophageal cancer cell proliferation in vitro (P<0.05) and caused cell cycle G₁ phase block, as determined by flow cytometric analysis (P<0.05). Overall, the soluble rhC2ORF40 protein with high purity and biological activity was obtained, which suppressed esophageal cancer cells proliferation by inducing cell cycle G₁ phase block in vitro. Therefore, the soluble rhC2ORF40 protein could be potential biological therapy drug for esophageal carcinoma.

[Mechanism of loss of human esophageal cancer-related gene 4 (ECRG4) gene expression in esophageal squamous cell carcinoma cell line EC9706]

OBJECTIVE

To investigate the mechanism of loss of human esophageal cancer-related gene 4 (ECRG4) expression in esophageal squamous cell carcinoma (ESCC.)

METHODS

PCR-SSCP and DNA sequencing analysis were used to detect the mutation of ECRG4 exons in esophageal cancer and matched adjacent normal tissues of 80 patients. DNA bisulfite-modifying ssPCR sequencing assay was used to examine the methylation status of ECRG4 promoter in human esophageal squamous cell carcinoma EC9706 cells. The re-expression of ECRG4 mRNA was examined by RT-PCR in EC9706 cells, after treatment with either demethylation drug 5-aza-2'-deoxycytidine or arsenic trioxide.

RESULTS

No mutation in the four ECRG4 exons was found in all the ESCC and matched normal adjacent tissues. RT-PCR showed that 11 of 16 CpG islands of ECRG4 promoter were hypermethylated, while ECRG4 mRNA expression level was undetectable in the EC9706 cells. The ECRG4 mRNA was re-expressed after treatment with either demethylation drug 5-aza-2'-deoxycytidine or arsenic trioxide.

CONCLUSION

The epigenetic mechanism of methylation is a reason of loss of ECRG4 gene expression in the ESCC cell line EC9706.

A novel tumor suppressor gene ECRG4 interacts directly with TMPRSS11A (ECRG1) to inhibit cancer cell growth in esophageal carcinoma

BACKGROUND

The esophageal carcinoma related gene 4 (ECRG4) was initially identified and cloned from human normal esophageal epithelium in our laboratory (GenBank accession no.AF325503). ECRG4 has been described as a novel tumor suppressor gene associated with prognosis in esophageal squamous cell carcinoma (ESCC).

METHODS

In this study, binding affinity assay in vitro and co-immunoprecipitation experiment in vivo were utilized to verify the physical interaction between ECRG4 and transmembrane protease, serine 11A (TMPRSS11A, also known as ECRG1, GenBank accession no. AF 071882). Then, p21 protein expression, cell cycle and cell proliferation regulations were examined after ECRG4 and ECRG1 co-transfection in ESCC cells.

RESULTS

We revealed for the first time that ECRG4 interacted directly with ECRG1 to inhibit cancer cell proliferation and induce cell cycle G1 phase block in ESCC. Binding affinity and co-immunoprecipitation assays demonstrated that ECRG4 interacted directly with ECRG1 in ESCC cells. Furthermore, the ECRG4 and ECRG1 co-expression remarkably upregulatd p21 protein level by Western blot (P < 0.001), induced cell cycle G1 phase block by flow cytometric analysis (P < 0.001) and suppressed cell proliferation by MTT and BrdU assay (both P < 0.01) in ESCC cells.

CONCLUSIONS

ECRG4 interacts directly with ECRG1 to upregulate p21 protein expression, induce cell cycle G1 phase block and inhibit cancer cells proliferation in ESCC.

A novel tumor suppressor gene ECRG4 interacts directly with TMPRSS11A (ECRG1) to inhibit cancer cell growth in esophageal carcinoma

BACKGROUND

The esophageal carcinoma related gene 4 (ECRG4) was initially identified and cloned from human normal esophageal epithelium in our laboratory (GenBank accession no.AF325503). ECRG4 has been described as a novel tumor suppressor gene associated with prognosis in esophageal squamous cell carcinoma (ESCC).

METHODS

In this study, binding affinity assay in vitro and co-immunoprecipitation experiment in vivo were utilized to verify the physical interaction between ECRG4 and transmembrane protease, serine 11A (TMPRSS11A, also known as ECRG1, GenBank accession no. AF 071882). Then, p21 protein expression, cell cycle and cell proliferation regulations were examined after ECRG4 and ECRG1 co-transfection in ESCC cells.

RESULTS

We revealed for the first time that ECRG4 interacted directly with ECRG1 to inhibit cancer cell proliferation and induce cell cycle G1 phase block in ESCC. Binding affinity and co-immunoprecipitation assays demonstrated that ECRG4 interacted directly with ECRG1 in ESCC cells. Furthermore, the ECRG4 and ECRG1 co-expression remarkably upregulatd p21 protein level by Western blot (P < 0.001), induced cell cycle G1 phase block by flow cytometric analysis (P < 0.001) and suppressed cell proliferation by MTT and BrdU assay (both P < 0.01) in ESCC cells.

CONCLUSIONS

ECRG4 interacts directly with ECRG1 to upregulate p21 protein expression, induce cell cycle G1 phase block and inhibit cancer cells proliferation in ESCC.

The candidate tumor suppressor gene ECRG4 inhibits cancer cells migration and invasion in esophageal carcinoma

Background

The esophageal cancer related gene 4 (ECRG4) was initially identified and cloned in our laboratory from human normal esophageal epithelium (GenBank accession no.AF325503). ECRG4 was a new tumor suppressor gene in esophageal squamous cell carcinoma (ESCC) associated with prognosis. In this study, we investigated the novel tumor-suppressing function of ECRG4 in cancer cell migration, invasion, adhesion and cell cycle regulation in ESCC.

Methods

Transwell and Boyden chamber experiments were utilized to examined the effects of ECRG4 expression on ESCC cells migration, invasion and adhesion. And flow cytometric analysis was used to observe the impact of ECRG4 expression on cell cycle regulation. Finally, the expression levels of cell cycle regulating proteins p53 and p21 in human ESCC cells transfected with ECRG4 gene were evaluated by Western blotting.

Results

The restoration of ECRG4 expression in ESCC cells inhibited cancer cells migration and invasion (P < 0.05), which did not affect cell adhesion capacity (P > 0.05). Furthermore, ECRG4 could cause cell cycle G1 phase arrest in ESCC (P < 0.05), through inducing the increased expression of p53 and p21 proteins.

Conclusion

ECRG4 is a candidate tumor suppressor gene which suppressed tumor cells migration and invasion without affecting cell adhesion ability in ESCC. Furthermore, ECRG4 might cause cell cycle G1 phase block possibly through inducing the increased expression of p53 and p21 proteins in ESCC.

Kif18A is involved in human breast carcinogenesis

Microtubule (MT) kinesin motor proteins orchestrate various cellular processes (e.g. mitosis, motility and organelle transportation) and have been implicated in human carcinogenesis. Kif18A, a plus-end directed MT depolymerase kinesin, regulates MT dynamics, chromosome congression and cell division. In this study, we report that Kif18A is overexpressed in human breast cancers and Kif18A overexpression is associated with tumor grade, metastasis and poor survival. Functional analyses reveal that ectopic overexpression of Kif18A results in cell multinucleation, whereas ablation of Kif18A expression significantly inhibits the proliferative capability of breast cancer cells in vitro and in vivo. Inhibition of Kif18A not only affects the critical mitotic function of Kif18A but also decreases cancer cell migration by stabilizing MTs at leading edges and ultimately induces anoikis of cells with inactivation of the phosphatidylinositol 3-kinase-Akt signaling pathway. Together, our results indicate that Kif18A is involved in human breast carcinogenesis and may serve as a potential therapeutic target for human breast cancer.