[Lung squamous cell carcinoma-related genes cloned by using suppression subtractive hybridization].

OBJECTIVE

To identify genes differentially expressed in human lung squamous cell carcinoma (LSCC).

METHODS

A subtracted cDNA library of human LSCC constructed by using suppression subtracted hybridization (SSH) method was screened. Clones representing mRNAs that were truly differentially expressed in LSCC but not in its adjacent non-cancerous tissues were identified by semi-quantitative RT-PCR in 12 patients with LSCC. Partial novel genes were detected by Northern blot.

RESULTS

Ten differentially expressed gene cDNA fragments of LSSC were obtained by SSH. Among them six were known genes; two sequences were identified but their functions were unknown (hypothetical protein); two were novel (GenBank accession numbers AF363068 and AY032661, respectively). The results from semiquantitative RT-PCR showed that the transcription expression level of PPP1CB, calumenin, S100A2, HSNOV1, OCIA and AY032661 was down-regulated in some LSCC cases, while the transcription of HSP90, ferritin, gp96 and AF363068 was up-regulated in others.

CONCLUSIONS

Six known genes identified by SSH technique have been implicated in the pathogenesis of lung carcinogenesis, or they are involved in immunological defense mechanism in human body. Two hypothetical proteins probably also play an important role in the pathogenesis of lung cancer. The function of the two novel genes in lung carcinogenesis are under investigation.