Imaging Hypoxia and Cancer Stem Cells

我们在上一个资助期的研究重点是了解缺氧和 干细胞样乳腺癌细胞（SBCC）标志物，如CD 44，并了解靶向缺氧的影响 和胆碱代谢对其表达的影响。这些研究将缺氧确定为CD 44的调节剂。缺氧 诱导因子（HIF）沉默减少，但不能消除，CD 44表达，在原发性和转移性肿瘤， 肿瘤，并以CD 44表达依赖性方式减少来自这些肿瘤的转移。人 在乳腺癌中，我们观察到CD 44在乳腺癌细胞和癌相关组织中的强表达。 成纤维细胞（CAF）与直长胶原1（Col 1）纤维密切相关，这是典型的成纤维细胞（CAF）， 侵袭性转移性细胞外基质（ECM）表型。我们的数据突出了理解的重要性 CD 44在形成ECM，包括Col 1纤维，胆碱代谢，血管形成， 以及在侵袭和转移中。CD 44也是三阴性乳腺癌的重要靶点 （TNBC），其中化疗是目前唯一的治疗手段。使用抗体的初步研究 基于光疗法（PT）消除表达CD 44的癌细胞显示出肿瘤的显著减少， 在表达⑶ 44的三阴性MDA-MB-231人乳腺癌异种移植物中的体积。这些数据 塑造了这次更新申请的新方向。在目标1中，我们将了解CD 44在以下方面的作用： 改变Col 1纤维模式，吸引CAF，改变胆碱代谢，改变血管形成， 在MDA-MB-231、SUM-159和SUM-149 TNBC异种移植物中， 表达短发夹RNA（shRNA）以下调CD 44。分子和功能的应用 成像来扩展我们对CD 44作为一种已知影响生存和治疗的分子的理解 结果对于改善TNBC以及其他CD 44表达的癌症的治疗策略至关重要。 与干细胞样表型相关。在目标2中，我们将开发和优化基于抗体的CD 44 PT 在MDA-MB-231、SUM-159和SUM-149 TNBC异种移植物中表达癌细胞和CAF，以及在MMTV-231中表达癌细胞和CAF。 PyV MT GEMM（基因工程小鼠模型）乳腺癌，并确定对肿瘤的影响 生长、转移、CAFs、Col 1纤维模式、胆碱代谢和血管形成。作为这一目标的一部分，我们 将开发导管和内窥镜策略，以检测和治疗未来人类表达CD 44的肿瘤。 PT的应用。尽管对化疗有初步反应，但TNBC复发，显示难治性药物- 耐药和转移早于其他亚型。对有效精确度的迫切需求尚未得到满足 TNBC的药物使用酞菁染料如与CD 44抗体缀合的IR 700的PT提供了一种用于治疗癌症的方法。 安全且特异性的策略，以明确的翻译路径消除表达CD 44的癌细胞和CAF。

Our studies during the previous funding period focused on understanding the relationship between hypoxia and stem like breast cancer cell (SBCC) markers such as CD44, and understanding the effect of targeting hypoxia and choline metabolism on their expression. These studies identified hypoxia as a regulator of CD44. Hypoxia inducible factor (HIF) silencing reduced, but did not eliminate, CD44 expression in primary and metastatic tumors, and decreased metastasis from these tumors in a CD44 expression dependent manner. In human breast cancers, we observed strong expression of CD44 in breast cancer cells and in cancer associated fibroblasts (CAFs) that were closely associated with straight long collagen 1 (Col1) fibers that are typical of an invasive metastatic extracellular matrix (ECM) phenotype. Our data highlight the importance of understanding the functional roles of CD44 in shaping the ECM, including Col1 fibers, in choline metabolism, vascularization, and in invasion and metastasis. CD44 also presents an important target in triple negative breast cancer (TNBC) where chemotherapy is currently the only recourse for treatment. Preliminary studies using antibody based phototherapy (PT) to eliminate CD44 expressing cancer cells showed a dramatic reduction of tumor volume in a CD44 expressing triple negative MDA-MB-231 human breast cancer xenograft. These data have shaped the new directions of this renewal application. In Aim 1 we will understand the role of CD44 in modifying Col1 fiber patterns, attracting CAFs, modifying choline metabolism, altering vascularization and hypoxia, and decreasing invasion and metastasis in MDA-MB-231, SUM-159 and SUM-149 TNBC xenografts expressing short hair pin RNA (shRNA) to downregulate CD44. The applications of molecular and functional imaging to expand our understanding of CD44 as a molecule that is known to influence survival and treatment outcome are essential for improving treatment strategies for TNBC as well as other cancers where CD44 is associated with a stem cell like phenotype. In Aim 2 we will develop and optimize antibody based PT of CD44 expressing cancer cells and CAFs in MDA-MB-231, SUM-159 and SUM-149 TNBC xenografts and the MMTV- PyV MT GEMM (genetically engineered mouse model) of breast cancer, and determine the effect on tumor growth, metastasis, CAFs, Col1 fiber patterns, choline metabolism and vascularization. As part of this aim we will develop catheter and endoscopy strategies to detect and treat CD44 expressing tumors for future human applications of PT. Despite an initial response to chemotherapy, TNBCs relapse, display refractory drug- resistance, and metastasize earlier than other subtypes. There is an urgent unmet need for effective precision medicine of TNBC. PT using a phthalocyanine dye such as IR700 conjugated to CD44 antibody provides a safe and specific strategy to eliminate CD44 expressing cancer cells and CAFs with a clear translational path.