It is prevailingly thought that estrogen signaling is not involved in development of estrogen receptor (ER)-negative breast cancer. However, there is evidence indicating that ovariectomy prevents the development of both ER-positive and -negative breast cancer, suggesting that estrogen signaling is involved in the development of ER-negative breast cancer. Previously, our laboratory cloned a variant of ER-α, ER-α36, and found that ER-α36 mediated non-genomic estrogen signaling and is highly expressed in ER-negative breast cancer cells. In this study, we found that ER-α36 was highly expressed in 10/12 cases of triple-negative breast cancer. We investigated the role of mitogenic estrogen signaling mediated by ER-α36 in malignant growth of triple-negative breast cancer MDA-MB-231 and MDA-MB-436 cells that express high levels of ER-α36 and found these cells were strongly responded to mitogenic estrogen signaling both in vitro and in vivo. Knock-down of ER-α36 expression in these cells using the shRNA method diminished their responsiveness to estrogen. ER-α36 physically interacted with the EGFR/Src/Shc complex and mediated estrogen-induced phosphorylation of EGFR and Src. EGFR signaling activated ER-α36 transcription through an AP1 site in the ER-α36 promoter and ER-α36 expression was able to stabilize EGFR protein. Our results thus demonstrated that ER-α36 mediates non-genomic estrogen signaling through the EGFR/Src/ERK signaling pathway in ER-negative breast cancer cells and suggested that a subset of ER-negative breast tumors that express ER-α36 retain responsiveness to mitogenic estrogen signaling.

Edited by Robert BaroukiKeywords: Promoter Estrogen receptor ER-a36 Breast cancer a b s t r a c t Recently, we identified and cloned a membrane-based estrogen receptor (ER), ER-a36, which is transcribed from a previously unidentified promoter in the first intron of the original ER-a gene. We cloned the 5 0 flanking region of ER-a36 and found the cloned DNA sequence possessed strong promoter activity. A single transcription initiation site was mapped and a number of putative regulatory elements for various transcription factors such as the Wilms' tumor suppressor, WT1 and estrogen receptor (ER) were identified in this region. Transient co-transfection experiments further demonstrated that ER-a suppresses ER-a36 promoter activity in an estrogen-independent manner, which can be released by ER-a36 itself.

BackgroundTransgelin is an actin-binding protein that promotes motility in normal cells. Although the role of transgelin in cancer is controversial, a number of studies have shown that elevated levels correlate with aggressive tumor behavior, advanced stage, and poor prognosis. Here we sought to determine the role of transgelin more directly by determining whether experimental manipulation of transgelin levels in colorectal cancer (CRC) cells led to changes in metastatic potential in vivo.MethodsIsogenic CRC cell lines that differ in transgelin expression were characterized using in vitro assays of growth and invasiveness and a mouse tail vein assay of experimental metastasis. Downstream effects of transgelin overexpression were investigated by gene expression profiling and quantitative PCR.ResultsStable overexpression of transgelin in RKO cells, which have low endogenous levels, led to increased invasiveness, growth at low density, and growth in soft agar. Overexpression also led to an increase in the number and size of lung metastases in the mouse tail vein injection model. Similarly, attenuation of transgelin expression in HCT116 cells, which have high endogenous levels, decreased metastases in the same model. Investigation of mRNA expression patterns showed that transgelin overexpression altered the levels of approximately 250 other transcripts, with over-representation of genes that affect function of actin or other cytoskeletal proteins. Changes included increases in HOOK1, SDCCAG8, ENAH/Mena, and TNS1 and decreases in EMB, BCL11B, and PTPRD.ConclusionsIncreases or decreases in transgelin levels have reciprocal effects on tumor cell behavior, with higher expression promoting metastasis. Chronic overexpression influences steady-state levels of mRNAs for metastasis-related genes.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-016-2105-8) contains supplementary material, which is available to authorized users.

It is prevailingly thought that the antiestrogens tamoxifen and ICI 182, 780 are competitive antagonists of the estrogen-binding site of the estrogen receptor-alpha (ER-α). However, a plethora of evidence demonstrated both antiestrogens exhibit agonist activities in different systems such as activation of the membrane-initiated signaling pathways. The mechanisms by which antiestrogens mediate estrogen-like activities have not been fully established. Previously, a variant of ER-α, EP–α36, has been cloned and showed to mediate membrane-initiated estrogen and antiestrogen signaling in cells only expressing ER-α36. Here, we investigated the molecular mechanisms underlying the antiestrogen signaling in ER-negative breast cancer MDA-MB-231 and MDA-MB-436 cells that express high levels of endogenous ER-α36. We found that the effects of both 4-hydoxytamoxifen (4-OHT) and ICI 182, 780 (ICI) exhibited a non-monotonic, or biphasic dose response curve; antiestrogens at low concentrations, elicited a mitogenic signaling pathway to stimulate cell proliferation while at high concentrations, antiestrogens inhibited cell growth. Antiestrogens at l nM induced the phosphorylation of the Src-Y416 residue, an event to activate Src, while at 5 µM induced Src-Y527 phosphorylation that inactivates Src. Antiestrogens at 1 nM also induced phosphorylation of the MAPK/ERK and activated the Cyclin D1 promoter activity through the Src/EGFR/STAT5 pathways but not at 5 µM. Knock-down of ER-α36 abrogated the biphasic antiestrogen signaling in these cells. Our results thus indicated that ER-α36 mediates biphasic antiestrogen signaling in the ER-negative breast cancer cells and Src functions as a switch of antiestrogen signaling dependent on concentrations of antiestrogens through the EGFR/STAT5 pathway.

We aimed to investigate the risk factors for cervical intraepithelial neoplasia (CIN) in Jiexiu, Shanxi Province, China. Twenty thousand eligible married women (age: 18-65 years) were administered with a questionnaire on potential risk factors for CIN and underwent liquid based Pap test. All women with abnormal cytological results underwent colposcopy with biopsy. Based on the biopsy pathology results, women were then assigned to either study group (with CIN) or control group (negative for histological results and volunteered to participate in the follow up study). The women in both study group and control group underwent vaginal microflora detection and dietary survey. The potential risk factors were analyzed by using ordinal logistic regression. Among the 20,000 women ne 1,438 women (7.19%) had cytologic abnormalities and 410 (2.05%) women were diagnosed histologically with CIN lesions, including 317 (1.58%) with CIN1, 93 (0.50%) with CIN2/3and 11 (55/100,000) with squamous cell carcinoma (SCC). The average daily dietary folate intake was significantly lower in the study group (344.61±153.07μg) than in the control group (371.50±166.58μg; P<0.001). Multivariate analysis demonstrated that age of 56-65 years, farming as the husband's occupation, unwashing the vulva after sexual intercourse, and low self-reported folate intake were positively associated with CIN development and might have contribution to the increased CIN incidence in this population. These findings may provide help to develop the strategies to reduce the risk of cervical cancer in China.

Genetic alteration involving N6-methyladenosine (m6A) regulatory genes is a frequent characteristic of multiple tumors. Nevertheless, little is known regarding their genetic alteration signatures and prognostic values in head and neck squamous cell carcinoma (HNSCC). In this study, RNA sequence profiles and copy number variation (CNV) data of 506 HNSCC patients were downloaded from The Cancer Genome Atlas (TCGA) database. Correlation analysis involving alteration of m6A regulatory genes, clinicopathological characteristics, and patient survival was performed using R language. The results suggest that alteration of m6A regulatory genes was correlated with clinical staging. Patients with high expression of ALKBH5, FTO, METTL14, WTAP, YTHDC1, YTHDF1, and YTHDF2 had poor overall survival (OS) than those with low expression. Univariate and multivariate Cox regression analyses showed that ALKBH5 and YTHDC2 were independent risk factors for OS. However, patients with high YTHDC2 expression had better OS. Moreover, according to machine learning results, YTHDC2 was found to be the most important gene among the 10 m6A regulators. Additionally, high expression of YTHDC2 was correlated with activation of apoptosis and ubiquitin-mediated proteolysis. Here, we identified alterations to m6A regulatory genes in HNSCC for the first time and found that seven m6A regulators were associated with poor prognosis, especially ALKBH5, whereas YTHDC2 was associated with better prognosis. These m6A-related regulators could act as novel prognostic biomarkers for HNSCC. Our findings provide clues for understanding RNA epigenetic modifications in HNSCC.

Background/Objectives:To investigate the effect of folate status on cervical intraepithelial neoplasia (CIN) progression and its relationship with high-risk human papillomavirus (hrHPV).Subjects/Methods:We evaluated 20 000 sexually active women aged <65 years in Yangqu County by using a questionnaire; the subjects were also screened using the ThinPrep cytologic test (TCT). Patients with abnormal TCT results (other than glandular cell abnormalities) who were willing to provide informed consent were further diagnosed using colposcopy and histopathological examination. We investigated 247 cases of low-grade cervical squamous intraepithelial lesions (LSIL), 125 cases of high-grade cervical squamous intraepithelial lesions (HSIL) and 877 controls. A 24-item food frequency questionnaire was filled out by the investigator to estimate the consumption of dietary folate. Positivity for hrHPV from residual exfoliated cervical cells was tested; serum folate was also measured.Results:The hrHPV infection rate in HSIL patients (77.6%) was higher than that in LSIL (33.2%) and control (32.0%) patients. Dietary folate intakes in controls, LSIL and HSIL were 306.9±176.6, 321.8±168.0 and 314.7±193.8 μg/kcal, respectively. The levels of serum folate in controls, LSIL and HSIL were 18.2±7.9, 15.9±7.1 and 14.3±7.5 nmol/l, respectively. Increased CIN correlated with higher rates of hrHPV infection and lower levels of serum folate.Conclusions:Low levels of serum folate may increase the risk of CIN progression. Furthermore, potential synergy may exist between low serum folate levels and hrHPV infection to promote CIN development.

Small-molecule inhibitors targeted MAPK have been wildly used for some cancer therapeutics as a biologically viable model, but no one has been used for cervical caner. ERK1/2, one of MAPK kinases, is expressed high in cervical cancer tissue. The aim of the present study was to evaluate the effects of ERK1/2 inhibitor U0126 on proliferation and apoptosis of cervical cancer cells and appraise the correlated mechanism of the effects. In this study, the cell proliferation of Hela and C33A cervical cancer cells was tested by Cell Counting Kit-8 (CCK8) assay and cell counting after treated with ERK1/2 inhibitor U0126. The cell cycle and apoptosis were evaluated by flow cytometry (FCM). The protein levels of ERK1/2 and c-Fos and c-Jun were detected by Western blot. The results indicated that after down-regulating ERK1/2 proteins with the inhibitor U0126, Hela and C33A cells proliferation was inhibited, cell apoptosis was promoted, the proportions of G0/G1 stage in cell cycle increased, and G2/M stages decreased. After down-regulating ERK1/2 proteins of Hela and C33A cells, the expression levels of p-c-Fos protein decreased, while p-c-Jun protein increased. The results of this study indicated that ERK1/2 may promote the development of cervical cancer cells, suggesting ERK1/2 inhibitor may be used as an effective target for cervical cancer therapies working for. It might inhibit cervical cancer cells growth via regulating the transcription factors expression of c-Fos and c-Jun.