Abstract：Objective To detect the regulatory effect and diagnostic value of piR-128 on colorectal cancer through DNA methylase (DNMT) 3B. Methods A total of 54 patients diagnosed with colorectal cancer in the Department of General Surgery, the First Affiliated Hospital of Hebei North University from February 2018 to January 2020 were selected. The expression levels of piR-128 and DNMT1, DNMT3A, and DNMT3B in colorectal cancer tissues and adjacent normal tissues were detected by qRT-PCR. Spearman correlation analysis was used to evaluate the association between piR-128 and DNMT3B, and the relationship between patients with different levels of piR-128 and DNMT3B mRNA expression and their clinical characteristics was further analyzed. Receiver operation characteristic curve was used to evaluate the diagnostic and prognostic value of piR-128 in colorectal cancer. Human colorectal cancer cell line LIM1215 was selected and divided into control group (transfected with blank inhibitor and si-blank), piR-128 inhibitor group (transfected with piR-128 inhibitor), SI-DNMT3B group (transfected with si-DNMT3B) and inhibitor +Vector group (transfected with piR-128 inhibitor and DNMT3B Vector). Western blot and qRT-PCR were used to analyze the mutual regulatory relationship between piR-128 and DNMT3B. Transwell assay, cell scratch assay, and flow cytometry were used to analyze the effects of piR-128 and DNMT3B on the invasion, migration, and apoptosis of colorectal cancer cells. Results The levels of piR-128 and DNMT3B mRNA expression in colorectal cancer tissues were higher than those in adjacent normal tissues, and the differences were statistically significant (P ＜ 0.05). The results of correlation analysis showed that there was a positive correlation between the expression level of piR-128 and DNMT3BmRNA in colorectal cancer tissues (rs ＞ 0, P ＜ 0.05). The levels of piR-128 and DNMT3B mRNA in the piR-128 inhibitor group and inhibitor +Vector group were lower than those in the control group, the levels of DNMT3B mRNA in the si-DNMT3B group were lower than those in the control group, and the levels of DNMT3B mRNA in the inhibitor +Vector group were higher than those in the si-DNMT3B group, the protein levels of DNMT3B in the piR-128 inhibitor group, si-DNMT3B group, and inhibitor +Vector group were lower than those in the control group, and the protein level of DNMT3B in the inhibitor +Vector group were higher than those in the si-DNMT3B group, and the differences were statistically significant (P ＜ 0.05). The absorbance of si-DNMT3B group, piR-128 inhibitor group, and inhibitor +Vector group at 24, 36, 48, and 72 h were lower than those of the control group, and the differences were statistically significant (P ＜ 0.05). The invasion ability and migration rate of cells in the piR-128 inhibitor group, si-DNMT3B group, and inhibitor +Vector group were lower than those in the control group, and the apoptosis rate was higher than that in the control group, the invasion ability and migration rate of cells in the inhibitor +Vector group were higher than those in the si-DNMT3B group and piR-128 inhibitor group, and the apoptosis rate was lower than that in the si-DNMT3B group, the differences were statistically significant (P ＜ 0.05). Conclusion piR-128 participates in the progression of colorectal cancer through DNMT3B.
[1] Thrift AP. The epidemic of oesophageal carcinoma：Where are we now？[J]. Cancer Epidemiol，2016，41：88-95.
[2] Ozata DM，Gainetdinov I，Zoch A，et al. PIWI-interacting RNAs：small RNAs with big functions [J]. Nat Rev Genet，2019，20（2）：89-108.
[3] Yamashiro H，Siomi MC. PIWI-Interacting RNA in Dros-ophila：Biogenesis，Transposon Regulation，and Beyond [J]. Chem Rev，2017，118（8）：4404-4421.
[4] Weng W，Li H，Goel A，et al. Piwi-interacting RNAs（piRNAs）and cancer：Emerging biological concepts and potential clinical implications [J]. Biochim Biophys Acta Rev Cancer，2019，1871（1）：160-169.
[5] Czech B，Munafò M，Ciabrelli F，et al. piRNA-Guided Gen-ome Defense：From Biogenesis to Silencing [J]. Annu Rev Genet，2018，52（1）：131-157.
[6] Liu Y，Dou M，Song X，et al. The emerging role of the piRNA/piwi complex in cancer [J]. Mol Cancer，2019，18（1）：123.
[7] Ai L，Mu S，Sun C，et al. Myeloid-derived suppressor cells endow stem-like qualities to multiple myeloma cells by inducing piRNA-823 expression and DNMT3B activation [J]. Mol Cancer，2019，18（1）：88-95.
[8] Li B，Hong J，Hong M，et al. piRNA-823 delivered by multiple myeloma-derived extracellular vesicles promoted tumorigenesis through reeducating endothelial cells in the tumor environment [J]. Oncogene，2019，38（26）：5227-5238.
[9] Yan H，Wu QL，Sun CY，et al. piRNA-823 contributes to tumorigenesis by regulating de novo DNA methylation and angiogenesis in multiple myeloma [J]. Leukemia，2015，29（1）：196-206.
[10] 中华人民共和国国家卫生健康委员会.中国结直肠癌诊疗规范（2020年版）[J].中华外科杂志，2020，58（8）：561-585.
[11] 袁志恒，赵艳梅.piRNA/PIWI功能调控与精子发生[J].遗传，2017，39（8）：683-691.
[12] Ameli Mojarad M，Ameli Mojarad M，Shojaee B，et al. piRNA：a promising biomarker in early detection of gastrointestinal cancer [J]. Pathol Res Pract，2022，230：153757-153771.
[13] Tan L，Mai D，Zhang B，et al. PIWI-interacting RNA-36712 restrains breast cancer progression and chemoresistance by interaction with SEPW1 pseudogene SEPW1P RNA [J]. Mol Cancer，2019，18（1）：9-21.
[14] Mai D，Ding P，Tan L，et al. PIWI-interacting RNA-54265 is oncogenic and a potential therapeutic target in colorectal adenocarcinoma [J]. Theranostics，2018，8（19）：5213-5230.
[15] Cui L，Lou Y，Zhang X，et al. Detection of circulating tumor cells in peripheral blood from patients with gastric cancer using piRNAs as markers [J]. Clin Biochem，2011， 44（13）：1050-1057.
[16] Lin DC，Wang MR，Koeffler HP. Genomic and Epigenomic Aberrations in Esophageal Squamous Cell Carcinoma and Implications for Patients [J]. Gastroenterology，2018，154（2）：374-389.
[17] Vedeld HM，Goel A，Lind GE. Epigenetic biomarkers in gastrointestinal cancers：The current state and clinical perspectives [J]. Semin Cancer Biol，2018，51：36-49.
[18] Maesawa C，Tamura G，Nishizuka S，et al. Inactivation of the CDKN2 gene by homozygous deletion and de novo methylation is associated with advanced stage esophageal squamous cell carcinoma [J]. Cancer Res，1996，56（17）：3875-3878.
[19] Vychytilova-Faltejskova P，Stitkovcova K，Radova L，et al. Circulating PIWI-interacting RNAs piR-5937 and piR-28876 are promising diagnostic biomarkers of colon cancer [J]. Cancer Epidemiol Biomarkers Prev，2018，27（9）：1019-1028.
[20] Huang X，Zhou X，Hu Q，et al. Advances in esophageal cancer：A new perspective on pathogenesis associated with long non-coding RNAs [J]. Cancer Lett，2018，413：94-101.
[21] Chen S，Ben S，Xin J，et al. The biogenesis and biological function of PIWI-interacting RNA in cancer [J]. J Hematol Oncol，2021，14（1）：93-102.
[22] Liu T，Wang J，Sun L，et al. Piwi-interacting RNA-651 promotes cell proliferation and migration and inhibits apoptosis in breast cancer by facilitating DNMT1-mediated PTEN promoter methylation [J]. Cell cycle（Georgetown，Tex），20（16）：1603-1616.
[23] Eads CA，Lord RV，Kurumboor SK，et al. Fields of aberrant CpG island hypermethylation in Barrett’s esophagus and associated adenocarcinoma [J]. Cancer Res，2000，60（18）：5021-5026.
[24] Jing Z，Xi Y，Yin J，et al. Biological roles of piRNAs in colorectal cancer [J]. Gene，2021，769：145063-145077.
京公网安备 11010502046598号