Depletion of MRPL35 inhibits gastric carcinoma cell proliferation by regulating downstream signaling proteins.

BACKGROUND

Gastric carcinoma (GC) is a digestive system disease with high morbidity and mortality. However, early clinical detection is difficult, and the therapeutic effect for advanced disease is not satisfactory. Thus, finding new tumor markers and therapeutic targets conducive to the treatment of GC is imperative. MRPL35 is a member of the large subunit family of mitochondrial ribosomal protein. MRPL35 shows the characteristic of oncogene in colorectal cancer and esophageal cancer, which promotes the exploration of the correlation between MRPL35 and GC. We proposed that the expression of MRPL35 might be critical in GC.

AIM

To study the effect of knockdown on GC cell proliferation.

METHODS

The expression of in GC was evaluated based on data from the public tumor database UALCAN (www.ualcan.path.uab.edu). The effect of the expression of on the prognosis was evaluated with KMplot (www.kmplot.com). The expression of MRPL35 was assessed on the tissue microarray by immunohistochemistry and the level of mRNA in 25 pairs of clinical GC tissues and matched adjacent tissues was detected by quantitative reverse transcription-polymerase chain reaction. Celigo cell count assay, colony formation assay, and flow cytometry were used to assess the role of MRPL35 in GC cell proliferation and apoptosis . Additionally, tumor formation experiment in BALB/c nude mice was utilized to determine the effect of on GC cell proliferation. After knockdown of , related proteins were identified by isobaric tags for relative and absolute quantification analysis, and the expression of related proteins was detected by Western blot.

RESULTS

The expression of MRPL35 was up-regulated in GC ( = 1.77 × 10). The Kaplan-Meier plots of the overall survival indicated that high expression of MRPL35 was associated with a poor survival in GC. Compared with adjacent tissues, the expression of MRPL35 in GC tissues was increased, which was related to age ( = 0.03), lymph node metastasis ( = 0.007), and pathological tumor-node-metastasis stage ( = 0.024). Knockdown of inhibited GC cell proliferation and colony formation and induced apoptosis. Animal experiment results showed that knockdown of inhibited tumor formation in BALB/c nude mice. Western blotting analysis showed that after knockdown of , the expression of PICK1 and BCL-XL proteins decreased, and that of AGR2 protein increased.

CONCLUSION

Collectively, our findings demonstrate that knockdown of inhibits GC cell proliferation through related proteins including PICK1, BCL-XL, and AGR2.