TGF-β Signaling Pathway Genes Research Articles

Transforming growth factors β and their signaling pathway in renal cell carcinoma and peritumoral space—transcriptome analysis

PurposeThe aim of the study was to verify hypotheses: Are transforming growth factors TGFβ1-3, their receptors TGFβI-III, and intracellular messenger proteins Smad1-7 involved in the pathogenesis of kidney cancer? What is the expression of genes of the TGFβ/Smads pathway in renal cell carcinoma (RCC) tissues, peritumoral tissues (TME; tumor microenvironment), and in normal kidney (NK) tissue?.MethodsTwenty patients with RCC who underwent total nephrectomy were included into the molecular analysis. The mRNA expression of the genes was quantified by RT-qPCR.ResultsThe study showed that the expression of the genes of TGFβ/Smads pathway is dysregulated in both RCC and the TME: TGFβ1, TGFβ3 expression is increased in the TME in comparison to the NK tissues; TGFβ2, TGFβ3, TGFβRI, TGFβRIII, Smad1, Smad2, Smad3, and Smad6 are underexpressed in RCC comparing to the TME tissues; TGFβRI, TGFβRIII, and Smad2 are underexpressed in RCC in comparison to the NK tissues.ConclusionOn the one hand, the underexpression of the TGFβ signaling pathway genes within the malignant tumor may result in the loss of the antiproliferative and pro-apoptotic activity of this cytokine. On the other hand, the overexpression of the TGFβ/Smads pathway genes in the TME than in tumor or NK tissues most probably results in an immunosuppressive effect in the space surrounding the tumor and may have an antiproliferative and pro-apoptotic effect on non-neoplastic cells present in the TME. The functional and morphological consistency of this area may determine the aggressiveness of the tumor and the time in which the neoplastic process will spread.

Pan-Cancer analysis of the mutation frequency of genes in TGF-beta pathway.

e15113 Background: The TGF-β signaling pathway governs key cellular processes under physiologic conditions and deregulates in cancer, including a diverse and varied set of gene responses that range from cytostatic and apoptotic tumor-suppressive ones in early-stage tumors to proliferative, invasive, angiogenic, and oncogenic ones in advanced cancer. However, the genomics profiles of TGF-β signaling pathway genes are unclear. In this study, we evaluated the genomic features in Chinese pan-cancer patients and investigated the mutation frequency of genes in the TGF-β pathway. Methods: A total of 5420 patients consisting of 22 cancer types were enrolled in this study. Utilizing target next-generation sequencing (NGS) platform, genomic profiling of 599 cancer-related genes, including genes of TGF-β pathway (SMAD2/3/4, PDGFRB, CDH1, MDM2, CDKN1A, and CDKN2B), was performed on tumor tissue or blood samples. Results: We observed 25.57% (1386/5420) of cases harbored at least one alteration in the TGF-β pathway genes. The mutation frequency ranges 9.09% to 39.77% among the 22 cancer types, including 39.77% (247/621) in gastric cancer, 39.31 (320/814) in bowel cancer, 36.84% (7/19) in endometrial cancer, 11.11% (8/72) in esophageal cancer, 10.46% (7/67) in kidney cancer, and 9.09% (2/22) in the gastrointestinal stromal tumor, respectively. The mutation of tumor-promoting effects genes SMAD2/3/4, PDGFRB, CDH1and MDM2 in the TGF-β pathway were found in all cancer types and mainly occurred in CNS tumor, gastrointestinal stromal tumor, pancreatic cancer, sarcoma, gastric cancer, and bowel cancer. The tumor-suppressing effective genes CDKN1A and CDKN2B primarily mutated in melanoma, endometrial cancer, and kidney cancer. Approximately 21.77% of patients had CNV in the TGF-β pathway of all tumor types. The most frequently mutated TGF-β genes were MDM2 and CDKN2B, mainly altered in sarcoma, melanoma, and CNS Tumor. Conclusions: We found a unique genomic feature of the TGF-β pathway of Chinese pan-cancer patients. Targeting mutant of TGF-β pathway genes remains a potentially effective treatment in the future.

Profile of Podocyte Translatome During Development of Type 2 and Type 1 Diabetic Nephropathy Using Podocyte-Specific TRAP mRNA RNA-seq.

Podocyte injury is important in development of diabetic nephropathy (DN). Although several studies have reported single-cell-based RNA sequencing (RNA-seq) of podocytes in type 1 DN (T1DN), the podocyte translating mRNA profile in type 2 DN (T2DN) has not previously been compared with that of T1DN. We analyzed the podocyte translatome in T2DN in podocin-Cre; Rosa26fsTRAP; eNOS-/-; db/db mice and compared it with that of streptozotocin-induced T1DN in podocin-Cre; Rosa26fsTRAP; eNOS-/- mice using translating ribosome affinity purification (TRAP) and RNA-seq. More than 125 genes were highly enriched in the podocyte ribosome. More podocyte TRAP genes were differentially expressed in T2DN than in T1DN. TGF-β signaling pathway genes were upregulated, while MAPK pathway genes were downregulated only in T2DN, while ATP binding and cAMP-mediated signaling genes were downregulated only in T1DN. Genes regulating actin filament organization and apoptosis increased, while genes regulating VEGFR signaling and glomerular basement membrane components decreased in both type 1 and type 2 diabetic podocytes. A number of diabetes-induced genes not previously linked to podocyte injury were confirmed in both mouse and human DN. On the basis of differences and similarities in the podocyte translatome in T2DN and T1DN, investigators can identify factors underlying the pathophysiology of DN and novel therapeutic targets to treat diabetes-induced podocyte injury.

Immunosuppressive function of DPP4, a proinflammatory molecule, in inflammatory colitis

Abstract We and others have shown that dipeptidyl peptidase-4 (DPP4) promotes inflammation in a number of conditions. However, it’s role in inflammatory colitis is not fully understood. Here we examined the role of DPP4 in dextran sulfate sodium (DSS)-induced colitis model and T cell transfer model of chronic colitis. The expression of DPP4 was significantly decreased in the colon tissue of wild-type (WT) mice with colitis. The mortality and disease activity score were markedly increased in mice deficient for DPP4 (Dpp4−/−), compared to WT mice. Chimeric mice with Dpp4−/− bone marrow showed a similar disease severity to whole body DPP4 knockout mice in DSS induced colitis, suggesting that bone marrow-derived immune cells were responsible for the protective effect of DPP4 on colitis. Flow cytometry analysis indicated that DPP4 was mainly expressed in T cells and dendritic cells (DCs) in mesenteric lymph nodes. Using T cell transfer model of chronic colitis in Rag2−/− mice or Dpp4−/− Rag2−/− mice, we found that innate immune cells other than adaptive immune cells were responsible for the protective effect of DPP4. Subsequent flow cytometric analysis showed that DPP4 was mainly expressed on a DC subset that was responsible for the induction of regulatory T cells (Tregs) in the gut. RNA sequencing data also indicated that expression of genes in TGFβ signaling pathway was significantly reduced in Dpp4−/− mice, accompanied by an increased expression of multiple inflammatory genes. Co-transfer of WT Tregs protected Rag2−/− mice, but not Dpp4−/− Rag2−/− mice, from developing colitis after transfer of CD4+ naive T cells. Our data suggest that DPP4 expression on innate immune cells may be responsible for maintaining Treg’s suppressive function in colitis.

Polymorphisms in MicroRNA Target Sites of TGF-β Signaling Pathway Genes and Susceptibility to Allergic Rhinitis

Background: The polymorphisms inside microRNA target sites locating in the 3′-UTR region may introduce the micro­RNA-binding changes, which may regulate the gene expression and correlate with the potential diseases. Objectives: We aimed to investigate whether the polymorphisms in microRNA target sites of transforming growth factor beta (TGF-β) signaling pathway genes are associated with the susceptibility of mite-sensitized allergic rhinitis (AR) in a Han Chinese population. Methods: In this case-control study, 454 AR patients and 448 healthy controls were recruited. Three HapMap single-nucleotide polymorphisms (SNPs) were mapped to putative microRNA recognition sites and genotyped by TaqMan allelic discrimination assay. Results: The genotype and allele frequencies of 3 SNPs (rs1590 in TGFBR1; rs1434536 and rs17023107 in BMPR1B) showed lack of significant association with AR. However, in the subgroup analysis, the TG, GG, and TG/GG genotypes of rs1590 exhibited significantly increased risk of AR in the male subgroup (TG: adjusted OR = 1.57, 95% CI = 1.08–2.31; GG: adjusted OR = 1.76, 95% CI = 1.09–2.86; TG/GG: adjusted OR = 1.62, 95% CI = 1.13–2.33). The CT genotypes of rs17023107 might have potential to protect against AR in the patients age of <15 years (adjusted OR = 0.37, 95% CI = 0.14–0.95) and the males (adjusted OR = 0.48, 95% CI = 0.25–0.95). No significant association was found between SNPs and the total serum IgE level. Conclusions: In a Han Chinese population, stratified by age and gender, susceptibility to mite-sensitized AR may be associated with 2 SNPs (rs1590 and rs17023107) in microRNA target sites of TGF-β signaling pathway genes.

Stabilization of HIF-1α in Human Retinal Endothelial Cells Modulates Expression of miRNAs and Proangiogenic Growth Factors.

Retinal hypoxia is one of the causative factors of diabetic retinopathy and is also one of the triggers of VEGF release. We hypothesized that specific dysregulated miRNAs in diabetic retinopathy could be linked to hypoxia-induced damage in human retinal endothelial cells (HRECs). We investigated in HRECs the effects of chemical (CoCl2) hypoxia on the expression of HIF-1α, VEGF, PlGF, and of a focused set of miRNAs. We found that miR-20a-5p, miR-20b-5p, miR-27a-3p, miR-27b-3p, miR-206-3p, miR-381-3p correlated also with expression of TGFβ signaling pathway genes in HRECs, challenged with chemical hypoxic stimuli. In conclusion, our data suggest that retinal angiogenesis would be promoted, at least under HIF-1α activation, by upregulation of PlGF and other factors such as miRNAs, VEGFA, and TGFβ1.

P6501Recurrent genetic aberrations in bicuspid aortic valve disease patients with isolated severe aortic regurgitation

Abstract Background The etiology of bicuspid aortic valve disease (BAVD) is still unclear. Recent studies have demonstrated elevated prevalence of genetic defects in BAV patients with root phenotype, which includes aortic regurgitation and root-predominant dilatation. Purpose The present study intended to illustrate the feature of genetic defects among early-onset BAV patients with isolated severe aortic regurgitation. Methods From June 2015 to December 2017, whole exome sequencing was performed upon 27 BAVD patients with isolated severe aortic regurgitation under 45 years in our institution. Patients were categorized into right-left (R-L, n=16) and non-RL (n=11) cusp fusion types, and those with complex cardiac defects were excluded from the present study. Results Among 27 patients with a median age of 30.5 (18–44) years, only one was female with a rare left-non-coronary cusp fusion type. The prevalence of root phenotype was markedly higher in RL patients (56.3% vs 9.1%, p=0.018). In RL patients, the numbers of rare genetic variants (RGVs) were 15 in extracellular matrix genes, 8 in TGF-β signaling pathway genes, 2 in smooth muscle cell contraction apparatus genes, and 3 in familiar BAV related genes. In non-RL patients, the number of RGVs were 15, 3, 4, and 5, respectively. On the other hand, the number of RGVs in above gene clusters were 9, 6, 3, 2 in patients with a root phenotype, and 21, 5, 3, 6 in those without. Eight recurrent genetic variants were identified in 6 genes (see Table). An interesting observation was that ADAMTS2 variants were exclusively found among non-RL patients without root phenotype, as FBN2 variants among RL patients with root phenoype. Recurrent Rare Genetic Variants Gene Reference sequence Variant 1000G 1000G-East Asia Patients TGFBR2 NM_001024847.2 p.Val216Ile/c.646G&gt;A 0.004 0.018 A16, A23 TGFBR2 NM_001024847.2 p.Thr340Met/c.1019C&gt;T 0.003 0.015 A03, A05, A07 ADAMTS2 NM_014244.4 p.Gly1169Val/c.3506G&gt;T 0.0044 0.021 A03, A15 FBN2 NM_001999.3 p.Gly475Val/c.1424G&gt;T 0.0004 0.002 A19, A24 ELN NM_001278939.1 p.Pro93Leu/c.278C&gt;T 0.0014 0.0069 A22, A26 COL4A5 NM_033380.2 p.Gly953Val/c.2858G&gt;T 0.0079 0.03 A11, A17 MYLK NM_053025.3 p.Ser243Trp/c.728C&gt;G 0.0002 0.001 A01, A02 MYLK NM_053025.3 p.Asp717Tyr/c.2149G&gt;T 0.0024 0.011 A04, A21 Conclusion Recurrent genetic variants could be identified in a cohort of early-onset BAVD patients with isolated severe aortic regurgitation and staggering male predominance. The incidence and clinical relevance of these variants should be validated in an extended real-world BAV cohort.

Hsa-miR-497 as a new regulator in TGFβ signaling pathway and cardiac differentiation process

Cardiosphere-derived cells (CDCs) contain cardiac stem cell subpopulations and are introduced as useful source for cardiac differentiation and therapy. Furthermore, research has highlighted miRNAs important role in various biological processes and cardiogenesis. Here, we intended to investigate the effect of hsa-miR-497 (miR-497) on TGFβ signaling pathway genes expression during the process of CDCs differentiation to cardiomyocytes. CDCs were successfully differentiated to the cardiac-like cells. In this study, we found that after cardiac differentiation induction, miR-497 expression was significantly decreased. Computational miRNA target prediction analyses revealed that TGFβ signaling pathway is a possible target of miR-497. Therefore, miR-497 was overexpressed in CDCs before the induction of differentiation. TGFβ1, TGFβR1, TGFβR2, and SMAD3 genes expression level was decreased after miR-497 overexpression. Also, immunocytochemistry and cell morphology analysis indicated that miR-497 overexpression affecting cardiac differentiation process. Finally, direct interaction of miR-497 with 3′-UTR sequence of TGFβR1 was supported through dual luciferase assay, consistent with miR-497 reported negative effect on SMAD3 expression. Accordingly, here a model of miR-497 involvement in regulation of TGFβ signaling pathway is introduced in which, side branches of TGFβ signaling pathway downregulate miR-497 to ensure upregulation of TGFβR1 and TGFβR2 and finally stronger TGFβ signaling.

The Molecular Differentiation of Anatomically Paired Left and Right Mantles of the Pacific Oyster Crassostrea gigas

Left-right (L-R) asymmetry is controlled by gene regulation pathways for the L-R axis, and in vertebrates, the gene Pitx2 in TGF-β signaling pathway plays important roles in the asymmetrical formation of organs. However, less is known about the asymmetries of anatomically identical paired organs, as well as the transcriptional regulation mechanism of the gene Pitx in invertebrates. Here, we report the molecular biological differences between the left and right mantles of an invertebrate, the Pacific oyster Crassostrea gigas, and propose one possible mechanism underlying those differences. RNA sequencing (RNA-seq) analysis indicated that the paired organs showed different gene expression patterns, suggesting possible functional differences in shell formation, pheromone signaling, nerve conduction, the stress response, and other physiological processes. RNA-seq and real-time qPCR analysis indicated high right-side expression of the Pitx homolog (cgPitx) in oyster mantle, supporting a conserved role for Pitx in controlling asymmetry. Methylation-dependent restriction-site associated DNA sequencing (MethylRAD) identified a methylation site in the promoter region of cgPitx and showed significantly different methylation levels between the left and right mantles. This is the first report, to our knowledge, of such a difference in methylation in spiralians, and it was further confirmed in 18 other individuals by using a pyrosequencing assay. The miRNome analysis and the TGF-β receptor/Smad inhibition experiment further supported that several genes in TGF-β signaling pathway may be related with the L/R asymmetry of oyster mantles. These results suggested that the molecular differentiation of the oyster's paired left and right mantles is significant, TGF-β signaling pathway could be involved in establishing or maintaining the asymmetry, and the cgPitx gene as one of genes in this pathway; the different methylation levels in its promoter regions between L/R mantles was the one of possible mechanisms regulating the left-right functional differentiation.

MicroRNA regulatory pathway analysis identifies miR-142-5p as a negative regulator of TGF-β pathway via targeting SMAD3.

MicroRNAs (miRNAs) are non-coding RNAs with functions of posttranscriptional regulation. The abnormally expressed miRNAs have been shown to be crucial contributors and may serve as biomarkers in many diseases. However, determining the biological function of miRNAs is an ongoing challenge. By combining miRNA targets prediction, miRNA and mRNA expression profiles in TCGA cancers, and pathway data, we performed a miRNA-pathway regulation inference by Fisher's exact test for enrichment analysis. Then we constructed a database to show the cancer related miRNA-pathway regulatory network (http://bioinfo.life.hust.edu.cn/miR_path). As one of the miRNAs targeting many cancer related pathways, miR-142-5p potentially regulates the maximum number of genes in TGF-β signaling pathway. We experimentally confirmed that miR-142-5p directly targeted and suppressed SMAD3, a key component in TGF-β signaling. Ectopic overexpression of miR-142-5p significantly promoted tumor cell proliferation and inhibited apoptosis, while silencing of miR-142-5p inhibited the tumor cell proliferation and promoted apoptosis in vitro. These findings indicate that miR-142-5p plays as a negative regulator in TGF-β pathway by targeting SMAD3 and suppresses TGF-β-induced growth inhibition in cancer cells. Our study proved the feasibility of miRNA regulatory pathway analysis and shed light on combining bioinformatics with experiments in the research of complex diseases.

Genetic variants of ADAM17 are implicated in the pathological process of Kawasaki disease and secondary coronary artery lesions via the TGF-β/SMAD3 signaling pathway.

Kawasaki disease (KD) is a systemic vasculitis childhood disease frequently complicating coronary artery lesions (CALs). Recently, the gene encoding a disintegrin and metalloprotease 17 (ADAM17) was found to modify vascular pathology in humans by differentially regulating the transforming growth factor-β (TGF-β) signaling pathway, which affects KD/CAL susceptibility. To explore the potential role of ADAM17 in KD occurrence and outcomes, we investigated the association of 28 single nucleotide polymorphisms (SNPs) in ADAM17 and three pathway genes of TGF-β signaling with KD phenotypes in a Han Chinese population, including 392 KD patients and 421 non-KD controls. Three ADAM17 SNPs showed an association with KD risk, which was further confirmed by haplotype analysis. The effect of ADAM17 on KD was also shown by multi-variable logistic regression analysis. In two-locus model analyses with SNPs in ADAM17 and TGF-β signaling pathway genes, stronger compound effects on the risk of KD and secondary CAL formation were observed relative to comparable single SNPs. Our results suggest that ADAM17 contributes to the KD risk and is involved in secondary CAL formation via the TGF-β/SMAD3 signaling pathway. This further enriches our understanding of the importance of the signaling pathway in KD occurrence and outcomes. • The transforming growth factor (TGF)-β/SMAD3 signaling pathway greatly influences susceptibility to Kawasaki disease (KD) and secondary coronary artery lesions (CALs) and/or the treatment response of intravenous immunoglobulin. • A disintegrin and metalloprotease 17 (ADAM17) effectively reduces TGF-β signaling by cleaving TGF-β receptor type-1, while ADAM17 genetic variants modify human vascular pathology by differentially regulating this signaling although it is unknown whether ADAM17 contributes to KD phenotypes. What is New: • ADAM17 genetic variants were shown to be associated with KD risk, even when excluding the influence of TGF-β signaling pathway genes, suggesting that ADAM17 is an important KD susceptibility-related genetic locus. • The more significant compound effects of two-locus models, combining single nucleotide polymorphisms (SNPs) in ADAM17 and other TGF-β signaling pathway genes including TGFB2 and SMAD3, on KD phenotypes relative to single SNPs suggest that ADAM17 is also involved in secondary CAL formation and confers the risk of KD/CALs via the TGF-β/SMAD3 signaling pathway.

Studying the Functions of TGF-β Signaling in the Ovary.

In mammals, ovulation is a multistep physiological process that includes preovulatory follicle growth, oocyte meiotic maturation, cumulus-oocyte complex (COC) expansion, follicle rupture, and luteinization. TGF-β signaling pathway has multiple functions in mammalian ovary, as its complexity in ovarian function has been demonstrated by mouse models with knockouts of TGF-β receptors and SMADs. We describe the protocol that we use to study functions of TGF-β signaling pathway in follicle development and ovulation. Because total knockout of TGF-β pathway components often causes embryonic lethality, which prevents further investigation of these genes in ovarian functions, people have generated ovarian cell type-specific knockout mouse strains for TGF-β signaling pathway genes. These mouse models are also described.

Abstract 4566: RNA-seq identifies a TGF-β signature that predicts response to preoperative bevacizumab in breast cancer.

Abstract Background: Gene expression profiles from tumor biopsies taken during preoperative therapy may identify markers associated with therapy benefit. We have previously shown that changes in TGF-β pathway activity following one dose of bevacizumab (B) are associated with pathologic complete response (pCR) (SABCS, 2012). Here we evaluated the ability of this signature to predict pCR following brief exposure to trastuzumab (T) or nab-paclitaxel (N). Methods: We sequenced transcriptomes of core biopsy RNA from 50 breast tumor pairs obtained from neoadjuvant clinical trials BrUOG 211A/211B. Patients were given one dose of B (n=15) or N (n=17) or T (n=18), followed by combination biologic/chemotherapy (HER2- with B/carboplatin/N; HER2+ with T/carboplatin/N). Paired-end sequencing (74bp) was performed using amplified total RNA from biopsies obtained pre/post 10 day exposure to run-in monotherapy. Transcript abundance and differential expression were estimated assuming Poisson-distributed read-counts. Significance-adjusted log2 fold change (sa-log2FC) of gene expression was calculated by diminishing statistically insignificant (p &amp;gt; 0.05) log2FC values by 100. sa-log2FC values of the TGF-β activity signature genes were used to cluster patients and the clusters were tested for enrichment of pCR cases. Prioritization of the genes in the TGF-β activity signature was performed with a shrunken centroid classifier using 3-fold cross-validation to identify an appropriate shrinkage threshold. Results: PCA and RNA-seq based PAM50 subtyping showed baseline and post-brief exposure samples clustering together across all patients. We identified significantly differentially expressed genes upon brief exposure to therapy associated with pCR in the B arm. Pathway analysis revealed TGF-β signaling, Cell Cycle, DNA Replication and Steroid Biosynthesis pathways to be enriched (p≤0.05) after multiple testing correction. Following the lead on TGF-β signaling, we derived a 107-gene TGF-β activity signature by combining a published TGF-β activity signature (Padua et al, 2008) with the pCR-associated KEGG TGF-β signaling pathway genes in our study. This signature showed a strong separation of pCR cases (p=0.004) by clustering. We further refined this using a shrunken centroid classifier to identify a 61-gene signature of TGF-β activity whose down-regulation is predictive of pCR in the B arm. Evaluation of the TGF-β signature in the T and N arms showed no association with pCR. Conclusions: TGF-β pathway genes whose activity is altered by brief exposure to bevacizumab are associated with pCR; a similar pattern was not observed following exposure to trastuzumab or nab-paclitaxel. This signature may provide an early indication of potential benefit from preoperative treatment with bevacizumab and combination chemotherapy. We are currently in the process of validating these results using a custom RT-PCR panel. Citation Format: Vinay Varadan, Kristy Miskimen, Sitharthan Kamalakaran, Angel Janevski, Nilanjana Banerjee, Nicole Williams, Maysa Abu-Khalaf, William Sikov, Nevenka Dimitrova, Lyndsay Harris. RNA-seq identifies a TGF-β signature that predicts response to preoperative bevacizumab in breast cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4566. doi:10.1158/1538-7445.AM2013-4566

Expression pattern of the transforming growth factor β signaling genes in human peripheral blood mononuclear cells after exercise—inflammatory aspects

The present study has focused on the identification of differences between the expression pattern of TGF-β signaling pathway genes in athletes after exercise. The study group consisted of three healthy cyclists, which were collected pre-exercise, immediately postexercise, and after 15 min of recovery. The analysis of the expression profile of genes related to the TGF-β signal transduction pathway was performed in peripheral blood mononuclear cells using HG-U133A oligonucleotide microarrays. A significant differential gene expression was recorded for RUNX3, TGFBR3, MLC1, and GRB2. The effect of physical exercise on immune response may be essential for human health. Moreover, alterations of TGF-β signaling can be involved in the process of adaptation of human organism to physical exertion.

Abstract 2604: Transforming growth factor beta signaling pathway variants and breast cancer risk: results from the Shanghai Breast Cancer Genetics Study

Abstract The transforming growth factor beta (TGF-β) signaling pathway is critical for several important cellular functions, and plays dual roles in the carcinogenic process. We systematically evaluated associations of common variants in TGF-β signaling pathway genes with breast cancer risk using a multi-staged, population-based, case-control study among Chinese women. In Stage I, 341 single nucleotide polymorphisms (SNPs) with MAFs ≤ 0.05 across 11 genes were evaluated among 2,926 cases and 2,380 controls. In Stage II, 20 SNPs with promising associations were evaluated among an additional 1,890 cases and 2,000 controls. Six SNPs from the TGFB2, TGFBR1, TGFBR2 and TGFBR3 genes were found to have consistent and significant associations in combined analyses with breast cancer risk in combined analyses of Stage I and Stage II data. One variant, TGFBR2 rs1078985, had not only consistent, but also highly significant associations with breast cancer risk in both study stages, as well as promising results from in silico analysis, and so was further evaluated. Results from additional genotyping in Stage III (2,475 cases and 2,343 controls) were also consistent; compared with the major allele homozygotes (GG) of rs1078985, reduced breast cancer risks were associated with AA(OR=0.75, 95%CI=0.60-0.94) and AG (OR=0.89, 95%CI=0.82-0.96) genotypes (Ptrend =0.0003). These data support a role for common genetic variation in TGF-β signaling pathway genes, specifically for a variant in TGFBR2, in breast cancer susceptibility. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2604. doi:1538-7445.AM2012-2604

Abstract 4149: Pathway-based serum microRNA profiling and late-stage non-small cell lung cancer survival

Abstract Non-small cell lung cancer (NSCLC) is one of the leading causes of cancer mortality in the world. Nearly half of NSCLC patients are diagnosed with late-stage (stage III or stage IV) disease with an overall 5-year survival rate of less than 15%. Deregulation of microRNAs (miRNAs) is involved in cancer development, progression, and prognosis. Circulating miRNAs have been suggested as promising biomarkers for early detection, diagnosis, and prognosis of cancer. This ongoing study is to utilize a pathway-based approach to screen and validate serum miRNA profiles as predictors of survival using a large patient cohort of 348 late-stage NSCLC patients. In the testing set, pre-treatment serum miRNA profiles of four good- (survival time &amp;gt; 24 months) and four poor-survival (survival time &amp;lt; 6 months) patients were compared by Taqman miRNA microarray. 145 highly expressed serum miRNAs were identified from initial screening and 37 of them were mapped onto the 3′UTRs of a panel of 23 genes in TGF-β signaling pathway using computer-assisted miRNA target prediction program. All 37 miRNA candidates were subject to large-scale single-probe quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). The expression level of serum miR-30d, which targets TGFBR2 and was a previously reported serum marker for early-stage lung cancer survival, was significantly higher in the poor-survival group than the good-survival group (P = 0.0208) in our study population of late-stage lung cancer. The level of serum miR-93-3p that targets SMAD7 was significantly higher in the poor-survival group than the good-survival group (P = 9x10−6). The 2-year overall survival rate in patients with high serum miR-93-3p expression was significantly lower than that in those with low expression with an adjusted HR of 1.59 (95% CI, 1.24 - 2.03) (P = 2x10−4). In contrast, serum level of let-7g, that targets SMAD2, TGFBR1 and the activin A receptor family was significantly lower in the poor-survival group than in the good-survival group (P = 7x10−4), and patients with high serum let-7g expression was associated with a significantly better two-year survival (HR=0.48, 95% CI, 0.37 - 0.62, P = 1x10−8). Our results suggest that serum miR-30d, miR-93-3p and let-7g may become valuable biomarkers for survival in late-stage NSCLC patients. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4149. doi:1538-7445.AM2012-4149

A high concentration of genistein down-regulates activin A, Smad3 and other TGF-β pathway genes in human uterine leiomyoma cells

Previously, we found that high doses of genistein show an inhibitory effect on uterine leiomyoma (UtLM) cell proliferation. In this study, using microarray analysis and Ingenuity Pathways Analysis™, we identified genes (up- or down-regulated, ≥ 1.5 fold, P ≤ 0.001), functions and signaling pathways that were altered following treatment with an inhibitory concentration of genistein (50 µg/ml) in UtLM cells. Downregulation of TGF-β signaling pathway genes, activin A, activin B, Smad3, TGF-β2 and genes related to cell cycle regulation, with the exception of the upregulation of the CDK inhibitor P15, were identified and validated by real-time RT-PCR studies. Western blot analysis further demonstrated decreased protein expression of activin A and Smad3 in genistein-treated UtLM cells. Moreover, we found that activin A stimulated the growth of UtLM cells, and the inhibitory effect of genistein was partially abrogated in the presence of activin A. Overexpression of activin A and Smad3 were found in tissue samples of leiomyoma compared to matched myometrium, supporting the contribution of activin A and Smad3 in promoting the growth of UtLM cells. Taken together, these results suggest that down-regulation of activin A and Smad3, both members of the TGF-β pathway, may offer a mechanistic explanation for the inhibitory effect of a high-dose of genistein on UtLM cells, and might be potential therapeutic targets for treatment of clinical cases of uterine leiomyomas.

Highlights of This Issue

Lymphoid malignancies occur at lower rates in Asians than other racial/ethnic groups in the United States. To explore this further, Clarke and colleagues examined incidence patterns of lymphoid malignancies among populations characterized by ethnicity, birthplace, residential neighborhood socioeconomic status, and ethnic enclave status. The authors used data from the California Cancer Registry and the U.S. Census. They found that incidence rates of follicular lymphoma (FL), chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), and nodular sclerosis Hodgkin lymphoma (NS HL) were significantly lower among foreign-born than U.S.-born Asians. These observations support strong roles of environmental factors in the causation of FL, CLL/SLL, and NS HL.Few studies have evaluated the impact of following recommended lifestyle behaviors on cancer, cardiovascular disease and all-cause mortality. McCullough and colleagues evaluated diet and lifestyle questionnaires from over 111,000 nonsmoking men and women from the Cancer Prevention Study (CPS)-II Nutrition Cohort and assessed subjects′ adherence to cancer prevention guidelines of the American Cancer Society. They report that the relative risk of all-cause mortality was lower for participants with high guideline adherence versus low. Similar inverse associations were found with cardiovascular disease and cancer mortality. This large study indicates that following cancer prevention guidelines for diet, exercise and alcohol consumption may substantially lower risk of premature mortality in older adults.It is hypothesized that exercise can lead to a decrease in breast cancer risk through several hormonal and nonhormonal mechanisms. Smith and colleagues used data from the Women in Steady Exercise Research (WISER) study to investigate the effects of aerobic exercise on premenopausal sex hormone levels. They report that while exercisers experienced significant increases in aerobic fitness, lean body mass, and decreases in percent body fat, there were no significant changes in sex hormone levels. These studies indicate that any favorable effects that moderate aerobic exercise may have on breast cancer risk are unlikely to be the consequence of changes in sex hormone levels.TGF-β acts as a suppressor of tumor initiation but can also promote later malignant stages. Scollen and colleagues evaluated 354 SNPs in seventeen TGF-β signaling pathway genes for their association with invasive breast cancer risk. Three SNPs were found to be associated with invasive breast cancer risk. Tumor subtype analysis revealed that one of the SNPs may be associated with increased risk of developing progesterone receptor negative (PR−) tumors. This large study agrees with previous reports and indicates that it is unlikely that other common variants in the TGF-β signaling pathway contribute significantly to breast cancer risk.