In primary lung tumors, squamous cell carcinoma (SCC) significantly expressed more CSTA compared to adenocarcinoma (p<0.00001), and higher expression of CSTA was significantly associated with lower tumor grade (p<0.01).
Furthermore, CSTA expression was observed in all 22 lymph node metastases analyzed.Relatively high levels of CSTA expression in tumors were correlated with tumor progression and advanced cancer stage, including lymph node metastasis.
We used the suppression subtractive hybridization technique to subtract cDNAs prepared from tumor and normal human esophageal samples. cDNA sequencing and reverse transcription polymerase chain reaction (RT-PCR) analysis of RNAs from human tumor and the normal esophagus revealed 10 differentially transcribed genes: CSTA, CRNN, CEACAM1, MAL, EMP1, ECRG2, and SPRR downregulated, and PLAUR, SFRP4, and secreted protein that is acidic and rich in cysteine upregulated in tumor tissue as compared with surrounding normal tissue.
Consistent with the mouse data, Stefin A expression correlated with disease-free survival (absence of distant metastasis) in a cohort of 142 primary tumours from breast cancer patients.
Evidence of amplification or rearrangement of 10 recognized cellular oncogenes (N-ras, mycL1, mycN, myc, H-ras, bcl1, H-stf1, sea, kraS2, and fos) was sought in tumor DNA.