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In breast cancer patients, primary chemotherapy is associated with the same survival benefits as adjuvant chemotherapy. Residual tumors represent a clinical challenge, as they may be resistant to additional cycles of the same drugs. Our aim was to identify differential transcripts expressed in residual tumors, after neoadjuvant chemotherapy, that might be related with tumor resistance. Hence, 16 patients with paired tumor samples, collected before and after treatment (4 cycles doxorubicin/cyclophosphamide, AC) had their gene expression evaluated on cDNA microarray slides containing 4,608 genes. Three hundred and eighty-nine genes were differentially expressed (paired Student's t-test, pFDR<0.01) between pre- and post-chemotherapy samples and among the regulated functions were the JNK cascade and cell death. Unsupervised hierarchical clustering identified one branch comprising exclusively, eight pre-chemotherapy samples and another branch, including the former correspondent eight post-chemotherapy samples and other 16 paired pre/post-chemotherapy samples. No differences in clinical and tumor parameters could explain this clustering. Another group of 11 patients with paired samples had expression of selected genes determined by real-time RT-PCR and CTGF and DUSP1 were confirmed more expressed in post- as compared to pre-chemotherapy samples. After neoadjuvant chemotherapy some residual samples may retain their molecular signature while others present significant changes in their gene expression, probably induced by the treatment. CTGF and DUSP1 overexpression in residual samples may be a reflection of resistance to further administration of AC regimen.

Background and Objective: Bile acid aspiration occurs in a variety of acute and chronic airway disorders. The consequence of bile acid aspiration and lung disease remains unclear. It was hypothesized that airway epithelium exposure to bile acids would induce fibrosis via production of connective tissue growth factor (CCN2), CCN2 is essential for transforming growth factor-beta (TGFbeta)-induced fibrogenesis and functions as a downstream mediator of TGF-beta action on fibroblasts., Methods: Human bronchial epithelial cells were grown on air-liquid interface culture inserts. Cells were stimulated with the major components of bile acids, chenodeoxycholic acid (CD) and glycochenodeoxycholic acid (GCD). RT-PCR and real-time quantitative PCR were used to detect mRNA expression. ELISA and western blotting were used to measure protein., Results: CD-stimulated airway epithelial cells produce CCN2 at both mRNA and protein levels in a dose-dependent manner. GCD failed to increase CCN2 production. CCN2 expression occurred via activation of p38 mitogen-activated protein (MAP) kinase and the downstream transcription factor ATF-2. Dexamethasone and the selective p38 MAP kinase inhibitor SB203580 successfully inhibited p38 MAP kinase, ATF-2 phosphorylation and subsequent CCN2 production. CD induced TGF-beta1 release from airway epithelium via the same signalling pathway. TGF-beta1 therefore enhanced CCN2production in an autocrine manner., Conclusion: Early intervention to stop these processes may be useful in preventing fibrogenesis in chronic airway diseases associated with bile acid exposure.