Triple-negative breast cancer (TNBC) represents a heterogeneous subtype of breast cancer that does not have negative estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) status. Because of the complexities and technical challenges, extensive collaborations with multidisciplinary teams and experts in clinical and basic health sciences are needed for the understanding of the mechanism and the development of effective therapies in the treatment of triple negative breast cancer.
We have been collaborating with the team from University of Colorado supervised by Dr. Brian S DeDecker. The two collaborated teams are working on the production of paclitaxel (Taxol) in soy plants and the bacteria-based therapy of triple negative breast cancer (TNBC) with a common concern on paclitaxel and tumor-associated macrophages, respectively. Focused on the highly glycolytic activity of TNBC tumor cells, the engineered bacteria are expected to intervene the metabolism of glucose, clear away lactic acid in the microenvironment, and thus re-boost macrophage driven anti-tumor immune responses by converting tumor-associated macrophages from non-inflammatory back to inflammatory phenotype. Interestingly, in addition to the known mechanism of the action of paclitaxel on microtubule stabilization, it was found that paclitaxel also promotes antitumor immunity through the transformation of M2-polarized macrophages to the M1-like phenotype in a TLR4-dependent manner.
- In plant synthetic biology, a mass spectrometric approach is being established so as to track the second step that hydroxylates the 5’ carbon on taxadiene and the T1 production from the taxadiene synthase in the first step. Genetically engineered bacteria obtained in this work are expected to be further enhanced as a versatile platform that can specifically deliver paclitaxel or other therapeutic payloads of clinical needs in the future.
- In molecular biology, we collaborate with CU-Boulder team to construct an engineered E. coli that live on lactate. The consumption of lactate by engineered bacteria is expected to eliminate acidic microenvironment that can re-boost macrophage for immune therapy. We have discussed the metabolic network of E. coli adaptively evolved on lactate.
- We are working on an efficient and versatile DNA assembly system called GoldenBraid to facilitate the building of genetic modules in engineering E. coli.
Dr. Bifeng Yuan is a distinguished professor in School of Public Health of Wuhan University. His research focuses on epigenetic modifications, metabolomics, nucleic acid damage and repair. Professor Yuan focuses on the analysis of the roles of epigenetic modifications, metabolomics, and nucleic acid damage and repair in cancer progression. His research provides us another direction to look into the occurrence of breast cancer. In contrast to genetics, epigenetics refers to the study of mechanisms that alter gene expression without altering the primary DNA sequence. It has been found that various epigenetic changes such as DNA methylation, histone modification, miRNA expression, and higher order chromatin structure affect gene expression. In fact, the progression of breast cancer involves complex and multi-step process that incorporates an accumulation of not only genetic but also epigenetic alterations. External and internal cellular microenvironmental factors influence the occurrence of these alterations that may drive tumorigenesis.
We discussed techniques of protein expression, experimental design and trouble shooting through online Tencent Meeting.
- RNA extraction and gel electrophoresis
- Avoid RNase contamination
- cDNA synthesis
- PCR
- Vector construction
- Protein expression and purification