Oxygen impact on tumor metastasis dormancy and therapy

 描述（由申请人提供）：从原发病灶扩散后，少数存活的癌细胞在远处部位建立驻留（微转移）。许多微转移瘤呈现休眠（静止）细胞表型，其特征为G 0/G1停滞，在生长形成临床明显的转移瘤之前可能持续数年至数十年;这些新出现的肿瘤几乎不可避免地导致死亡。不幸的是，微转移通常似乎是难治性的治疗剂，即使是那些对原发性肿瘤的成功，他们来自。这种情况在乳腺癌中尤其令人生畏，乳腺癌在复发之前可以潜伏十年或更长时间。 来自肿瘤微环境的信号已被证明一方面在维持这种休眠表型或另一方面促进细胞从静止中出现方面发挥关键作用。在我们实验室采用的新型全人类肝脏微生理系统（MPS）中培养乳腺癌细胞系已被证明可以可靠地诱导癌细胞休眠。传统上，快速增殖的癌细胞诉诸糖酵解以积累细胞分裂所需的大量代谢中间产物（“瓦尔堡效应”）。然而，表型休眠的癌细胞可能表现出不同的代谢特征，这可能是维持静止和成功的新治疗方法所必需的。我们的基本模型是休眠微转移适应低代谢和增殖状态与化疗耐药性和糖酵解通量减少一致。我们推测，氧张力水平将决定氧化磷酸化和糖酵解代谢之间的切换，从而影响休眠。 将通过细胞培养实验和免疫荧光定量葡萄糖摄取、糖酵解酶表达和细胞内ATP浓度来测量休眠癌细胞的基础糖酵解和氧化磷酸化通量，从而测试该模型。一种新型的血红蛋白氧载体（HBOC）将被引入到系统中，以调节癌细胞和肝组织所暴露的氧张力。灵敏的钌氧传感器将用于确定细胞所暴露的氧张力和跨组织氧梯度，以阐明氧张力对肿瘤休眠表型和细胞代谢的影响。最后，将选定的抗肿瘤药物（包括化疗药物多柔比星和顺铂）掺入肝脏MPS中，以确定疗效是否取决于癌细胞代谢状态，并同时监测对肝脏组织的毒性。 了解氧分压对休眠微转移表型，代谢和治疗敏感性的影响，预计将产生对基础肿瘤生物学的见解，并促进转化研究，以提高当前治疗（药物抢救）的疗效和发现新的治疗方法。

 DESCRIPTION (provided by applicant): Following dissemination from a primary lesion, a few surviving carcinoma cells establish residency in distant sites (micrometastases). Many micrometastases assume a dormant (quiescent) cellular phenotype, characterized by a G0/G1 arrest that may persist years to decades before outgrowth to form clinically evident metastases; these emergent tumors almost inexorably lead to death. Unfortunately, micrometastases often appear to be refractory to therapeutic agents, even ones that show success against the primary tumors from which they derive. This situation is particularly daunting in breast cancer that can li dormant for a decade or more before recurring. Signals from the tumor microenvironment have been shown to play a critical role in maintaining this dormant phenotype on the one hand or facilitating emergence from cellular quiescence on the other. Culture of breast cancer cell lines in a novel all human liver microphysiological system (MPS) our lab employs has been shown to reliably induce cancer cell dormancy. Traditionally, rapidly proliferating cancer cells resort to glycolysis in order to accumulate the massive amounts of metabolic intermediates required for cell division ("Warburg Effect"). However, the phenotypically dormant cancer cells may exhibit a different metabolic profile, which may be essential to both maintaining quiescence and successful novel treatment approaches. Our foundational model is that dormant micrometastases adapt a low metabolic and proliferative state concordant with chemoresistance and reduced glycolytic flux. We hypothesize that oxygen tension levels will dictate the switch between oxidative phosphorylation and glycolytic metabolism, and thereby impinge on dormancy. This model will be tested by measuring the basal glycolytic and oxidative phosphorylation fluxes of dormant cancer cells by quantifying glucose uptake, glycolytic enzyme expression, and intracellular ATP concentration through cell culture experiments and immunofluorescence. A novel hemoglobin-based oxygen carrier (HBOC) will be introduced to the system to modulate the oxygen tension to which the cancer cells and liver tissue are exposed. Sensitive ruthenium oxygen sensors will be used to determine the oxygen tension to which the cells are exposed and the trans-tissue oxygen gradient to elucidate the impacts of oxygen tension on tumor dormancy phenotype and cell metabolism. Finally, select anti-tumor agents, including the chemo-therapeutics doxorubicin and cisplatin, will be incorporated into the liver MPS to determine whether therapeutic efficacy is dependent on cancer cell metabolic state and concurrently monitor toxicities to the liver tissue. Understanding the influence of oxygen tension on dormant micrometastasis phenotype, metabolism, and treatment susceptibility is expected to yield insights into basic tumor biology and promote translational studies into improving the efficacy of current treatments (drug rescue) and the discovery of novel therapies.