PESTICIDE-INDUCED DIFFERENTIATION AND HETEROGENEITY IN BREAST CANCER CELLS

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。虽然已经提出农药通过雌激素途径致癌，但对于接触雌激素农药是否与生理有关尚未达成共识。本研究的目的是研究雌激素和非雌激素内分泌活性农药单独或组合（即混合物）如何增强或抑制乳腺癌细胞的内分泌反应，以及这些相互作用是否可能导致（直接或间接）对侵袭性表型的差异选择。需要验证的具体假设是，农药单独或联合使用可以重塑乳腺癌细胞群。前一年的目标和当前的目标是：(1)检测农药（单独和联合）对乳腺癌细胞中雌激素敏感基因转录的雌激素受体和非雌激素受体介导的影响；(2)阐明内源性细胞通路是否可能影响农药（单独或联合使用）对乳腺癌细胞中雌激素调节基因表达的作用。迄今为止，我们在T47-D和MCF-7乳腺癌细胞系中进行的全群体细胞培养研究获得了以下新数据：在DHEA-S（甾体底物）存在的情况下，HPTE与阿特拉津联合使用可增强雌激素反应元件（ERE）介导的基因表达，优于HPTE或阿特拉津单独治疗（即组合效应）：然而，仅在uM浓度下)，并且HPTE与IGF-1和tgf - α联合治疗比单独HPTE治疗增加了ere介导的基因表达。正在进行的研究旨在确定内分泌活性农药（单独使用或混合使用）是否会对癌细胞群体中细胞亚群的反应性产生不同的调节。我们已经开始解决这一目标，克服了与单个乳腺癌细胞成像相关的技术问题（注意：以前的“成像Subcore”已合并到本研究项目中），并评估了目前正在优化的两个系统的成像能力。目前的研究正在利用这些新的单细胞方法解决乳腺癌细胞对内分泌活性药物（如HPTE）反应性的异质性。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. While pesticide-induced carcinogenesis via estrogenic pathways have been suggested, a consensus on whether exposure to estrogenic pesticides is in fact physiologically relevant has yet to be reached. The goal of this study is to examine how estrogenic and non-estrogenic endocrine-active pesticides alone or in combination (i.e., mixtures) may augment or inhibit endocrine responses in breast cancer cells, and whether these interactions might result in a differential selection (directly or indirectly) for an invasive phenotype. The specific hypothesis to be tested is that pesticides alone and in combination can re-model breast cancer cell populations. The objectives of the previous year and current aims are: (1) to examine the estrogen receptor and non-estrogen receptor-mediated effects of pesticides (alone and in combination) on estrogen-sensitive gene transcription in breast cancer cells; and (2) to elucidate whether endogenous cellular pathways may influence the actions of pesticides (alone and in combination) on estrogen-regulated gene expression in breast cancer cells. To date our whole population cell culture studies in both T47-D and MCF-7 breast cancer cell lines have yielded the following new data: HPTE in combination with atrazine in the presence of DHEA-S (steroidal substrates) enhanced estrogen-response element (ERE)-mediated gene expression above HPTE or atrazine treatment alone (i.e., a combinatorial effect: however, only at uM concentrations), and HPTE in combination with IGF-1 and TGF-alpha augments ERE-mediated gene expression above treatment with HPTE alone. On-going research is aimed at determining whether endocrine-active pesticides (alone or in mixtures) may differentially regulate the responsiveness of subpopulations of cells within cancer cell societies. We have begun addressing this aim by overcoming technical considerations related to the imaging of single, individual breast cancer cells (note: the former "Imaging Subcore" has been merged into this research project), and have evaluated the imaging capabilities two systems which are being optimized currently. Current studies are addressing the heterogeneity in responsiveness of breast cancer cells to endocrine active agents (e.g., HPTE) using these novel single cell approaches.