Abstract
Background:We previously obtained a lncRNA RP3-326I13.1, which significantly upregulated by cisplatin resistance in lung adenocarcinoma (LAD), but the biological function and molecular mechanism is unclear. Methods:Expression levels of RP3-326I13.1 and HSP90B mRNA were estimated by qPCR from 57 pairs of LAD and NT samples without and with cisplatin. Knockdown and overexpression in A549/DDP and A549 cell lines by lentiviral- mediated techniques to observe changes in tumor behavior in A549/DDP and A549 cells, as well as tumorigenicity in experimental nude mice. The ranscriptome was sequenced to obtain downstream target molecules of RP3-326I13.1 and RNA-binding proteins were obtained using RNA pulldown. Results: QPCR showed that the expression level of RP3-326I13.1 and HSP90B mRNA in A549/DDP cells, LAD tissues and progressive LAD tissues (cisplatin treatment was not effective) were tangibly higher than that of A549 cells, adjacent tissues, and complete remission (P=0.0037, P=0.0181; P=0.0027, P=0.009 and P=0.002, P=0.007). RP3-326I13.1 markedly enhanced the proliferation, migrate, invasion, clonal proliferation ability of LAD cell lines and speed and weight of tumorigenicity in nude mice experiment while increased the proportion of G1 phase cells (P=0.019). RNA-pull down and mass spectrometry obtained RNA binding protein HSP90B and HSP90B clearly decreased proliferation, invasive ability while increased the apoptosis of LAD cell lines after knocked down. We found matrix metalloproteinase-13 (MMP-13) was RP3-326I13.1 downstream target gene. Conclusions: So, RP3-326I13.1 was a drug-resistant relative lncRNA promoted cisplatin resistance of lung adenocarcinoma by collaborating RNA binding protein HSP90B and upregulating downstream target molecule MMP13.