Kornelia Polyak

Kornelia Polyak is a Professor of Medicine at Harvard Medical School and a Senior Physician at Dana-Farber Cancer Institute. She is one of the world's leading authorities on breast cancer biology, with groundbreaking contributions to understanding intratumoral heterogeneity, cancer stem cells, clonal evolution, and the dynamic interplay between breast cancer cells and their microenvironment. Polyak began her scientific career with key discoveries in p21/CDK cell cycle regulation and apoptosis during her graduate training, before specializing in breast cancer biology at DFCI/HMS. Her laboratory has pioneered the use of single-cell approaches, clonal analysis, and large-scale genomics to dissect the cellular and genetic heterogeneity within individual breast tumors — revealing that each tumor is an evolving ecosystem of genetically distinct subclones. One of Polyak's most influential contributions is her characterization of cancer stem cells in breast cancer. She identified and characterized CD44high/CD24low breast cancer cells with tumor-initiating and self-renewal properties, demonstrating that these cells exist at the apex of a cellular hierarchy, resist standard therapies, and are responsible for tumor recurrence. This work was among the first to establish a functional cancer stem cell hierarchy in an epithelial solid tumor. Her laboratory has also systematically characterized the role of the tumor microenvironment — particularly cancer-associated fibroblasts (CAFs), immune cells, and the extracellular matrix — in driving breast cancer progression and heterogeneity. She demonstrated how paracrine signaling between breast cancer cells and stromal fibroblasts generates spatial patterns of gene expression and phenotypic diversity within tumors. Polyak's work on PIK3CA mutations in breast cancer has revealed how hotspot mutations in this frequently altered oncogene alter cellular metabolism, promote cancer stem cell properties, and drive resistance to targeted therapies. Her integration of evolutionary biology principles with cancer genomics has provided a sophisticated framework for understanding how tumors evolve under selective pressures from therapy, immune surveillance, and environmental factors — informing strategies to prevent or overcome treatment resistance.

Kornelia Polyak 是哈佛医学院医学教授和丹娜-法伯癌症研究所高级医师，是乳腺癌生物学领域的世界权威之一，在肿瘤内异质性、癌症干细胞、克隆进化以及乳腺癌细胞与微环境的动态相互作用方面有开创性贡献。 她鉴定和表征了具有肿瘤起始和自我更新特性的CD44high/CD24low乳腺癌细胞，是最早在上皮实体肿瘤中建立功能性癌症干细胞层级的研究之一。她的实验室还系统地表征了肿瘤相关成纤维细胞、免疫细胞和细胞外基质在驱动乳腺癌进展和异质性中的作用，并将进化生物学原理整合到癌症基因组学中以理解肿瘤如何在治疗压力下进化。