Curcumin promotes apoptosis, increases chemosensitivity, and inhibits nuclear factor kappaB in esophageal adenocarcinoma.

The transcription factor, nuclear factor kappaB (NF-kappaB), plays a central role as a key mediator of cell survival and proliferation, and its activation may confer increased tumor chemoresistance. Curcumin, an orally available naturally occurring compound, has been shown to inhibit NF-kappaB and has a potential role in cancer chemoprevention. We investigated the effects of curcumin on NF-kappaB activity, on cell viability, and as a chemosensitizing agent with 5-fluorouracil (5-FU) or cisplatin (CDDP) in esophageal adenocarcinoma (EAC). Oligonucleotide microarray analysis of 46 cases, consisting of Barrett metaplasia, low-grade dysplasia, high-grade dysplasia and EAC, showed increased expression of NF-kappaB and IkappaB kinase subunits and decreased effector caspase expression in EAC compared with Barrett metaplasia. Stromal expression of both IkappaB and phospho-IkappaB was detected in several EAC samples by tissue microarray analysis. Curcumin alone inhibited NF-kappaB activity and induced apoptosis in both Flo-1 and OE33 EAC cell lines as determined by Western blot analysis, NF-kappaB reporter assays, and Caspase-Glo 3/7 assays. It also increased 5-FU- and CDDP-induced apoptosis in both cell lines. These data suggest that activation of NF-kappaB and inhibition of apoptosis may play a role in the progression from Barrett metaplasia to EAC. In addition, curcumin, a well-known inhibitor of NF-kappaB activity, was shown to increase apoptosis and enhance both 5-FU- and CDDP-mediated chemosensitivity, suggesting that it may have potential application in the therapy of patients with EAC.

Upregulated INHBA expression may promote cell proliferation and is associated with poor survival in lung adenocarcinoma.

INTRODUCTION: The expression, mechanisms of regulation, and functional impact of INHBA (activin A) in lung adenocarcinoma (AD) have not been fully elucidated. METHODS: INHBA expression was examined in 96 lung samples (86 ADs, 10 normal lung) using oligonucleotide microarrays and 187 lung samples (164 ADs, 6 bronchioalveolar carcinomas, and 17 normal lung) using immunohistochemistry. The proliferation of AD cell lines H460 and SKLU1 was examined with WST-1 assays after treatment with recombinant activin A, follistatin, and INHBA-targeting small-interfering RNA. Cells were also treated with 5-aza-2' deoxycytidine and trichostatin A to investigate the role of epigenetic regulation in INHBA expression. RESULTS: Primary ADs expressed 3.1 times more INHBA mRNA than normal lung. In stage I AD patients, high levels of primary tumor INHBA transcripts were associated with worse prognosis. Immunohistochemistry confirmed higher inhibin betaA protein expression in ADs (78.7%) and bronchioalveolar carcinomas (66.7%) compared with normal lung (11.8%). H460 and SKLU1 demonstrated increased proliferation when treated with exogenous activin A and reduced proliferation when treated with follistatin or INHBA-targeting small-interfering RNA. INHBA mRNA expression in H460 cells was upregulated after treatment with trichostatin A and 5-aza-2' deoxycytidine. CONCLUSIONS: INHBA is overexpressed in AD relative to controls. Inhibin betaA may promote cell proliferation, and its overexpression is associated with worse survival in stage I AD patients. In addition, overexpression of INHBA may be affected by promoter methylation and histone acetylation in a subset of lung ADs.

INHBA overexpression promotes cell proliferation and may be epigenetically regulated in esophageal adenocarcinoma.

INTRODUCTION: The expression, mechanisms of regulation, and functional impact of activin (INHBA) in esophageal adenocarcinoma (EAC) have not been fully defined. METHODS: INHBA expression was examined in 46 esophageal samples (nine Barrett's metaplasia (BM); seven BM/low-grade dysplasia; eight low-grade dysplasia; seven high-grade dysplasia; 15 EAC) using oligonucleotide microarrays and real-time reverse transcription-polymerase chain reaction (RT-PCR) and in 90 tissue samples (79 EAC; 8 dysplastic; 3 BM) using immunohistochemistry (IHC). The proliferation of EAC cell lines FLO and OE-33 was examined after treatment with exogenous activin. The proliferation of OE-33 was also examined after treatment with the activin inhibitor follistatin and INHBA-targeting siRNA. OE-33 and FLO cells were treated with 5-aza-2'deoxycytidine (5-AZA) and trichostatin A to investigate the role of epigenetic regulation in INHBA expression. RESULTS: Primary EACs expressed 5.7-times more INHBA mRNA than BM samples on oligonucleotide microarray. Transcript overexpression in EAC relative to BM was confirmed on real-time RT-PCR. IHC suggested higher INHBA protein expression in EAC (69.6%) than in the dysplastic (37.5%) and BM samples (33.3%). FLO and OE-33 treated with activin demonstrated increased proliferation, and OE-33 cells treated with follistatin and INHBA-targeting siRNA demonstrated reduced proliferation, relative to untreated controls. Treatment of FLO cells with trichostatin A and 5-AZA up-regulated INHBA mRNA and protein production by real time RT-PCR and IHC. CONCLUSIONS: INHBA is overexpressed in EAC relative to dysplastic and BM tissue. INHBA overexpression may promote cell proliferation and may be affected by promoter demethylation and histone acetylation in EAC cell lines.

AZGP1 autoantibody predicts survival and histone deacetylase inhibitors increase expression in lung adenocarcinoma.

INTRODUCTION: The importance of alpha-2-glycoprotein 1, zinc (AZGP1) in lung adenocarcinoma (AD) remains largely unknown. Analysis of serum autoantibodies to tumor antigens combined with gene expression profiling of primary tumors may provide insight into the mechanisms underlying lung carcinogenesis and identify new AD biomarkers. METHODS: T7 phage cDNA libraries were used to identify AZGP1 autoantibodies in the serum of 473 patients (192 ADs, 192 matched controls, and 89 additional ADs for confirmation of findings). AZGP1 mRNA expression was examined in 86 ADs and 10 control lung tissue samples using oligonucleotide microarrays. AZGP1 protein expression was studied in 230 tissue samples (222 ADs; 8 controls) with immunohistochemistry. Kaplan-Meier analyses were used to correlate circulating autoantibody and tissue mRNA production with survival. AD cell lines A549 and SKLU1 were treated with 5-aza-2;-deoxycytidine (5-AZA) and trichostatin A (TSA) to examine the role of promoter methylation and histone deacetylation in the expression of AZGP1. Real-time polymerase chain reaction was used to quantify the effects of treatment. RESULTS: In patients with AD, AZGP1 autoantibodies were observed in 40% of serum samples. Autoantibody production correlated with improved overall 5-year survival (p = 0.002) and improved survival in those with stage I to II disease (p = 0.008). A verification analysis was performed for the survival benefit and found similar results with p values of 0.02 and 0.036, respectively. Although abundant mRNA expression was found in a subset of tumors, mRNA expression did not correlate with prognosis. In normal lung, AZGP1 mRNA and protein expression were low or absent, whereas in AD they were highly expressed in 31.3% and 42.8% of samples, respectively. To determine whether AZGP1 expression in this subset of tumors might be affected by epigenetic mechanisms, low AZGP1-expressing A549 and SKLU1 AD cell lines were treated with TSA and 5-AZA. A 713-fold and 169-fold increase in mRNA expression were noted on treatment with TSA, respectively. Treatment with 5-AZA had minimal effect on AZGP1 mRNA expression. CONCLUSIONS: The presence of AZGP1 serum autoantibody may be used as a prognostic marker in patients with AD. Furthermore, up-regulation of AZGP1 mRNA in AD may be affected by chromatin remodeling by means of histone acetylation.