Banca de QUALIFICAÇÃO: Dileep Kumar

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : Dileep Kumar
DATE: 24/01/2023
TIME: 14:00
LOCAL: Auditoium 2 do IB – Instituto de Biologia
TITLE:

Effect of Low-dose Chemotherapy in a Metastatic Pre-clinical Breast Cancer Model

KEY WORDS:

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PAGES: 30
BIG AREA: Ciências Biológicas
AREA: Biologia Geral
SUMMARY:

Breast cancer develops differently in each host, increasing the risk of metastasis. Metastasis happens when cancer cells leave the original tumor and create new tumor spots in the liver, lungs, or bones. 4T1 mouse mammary tumor cell line, which is a cell line used to produce pre-clinical breast cancer tumor models in experimental mice, can spread to distant locations, including lungs, bones, and bone marrow. One interesting point related to the 4T1 cell behavior is the ability to control normal hematopoiesis. For instance, the 4T1 cells can induce the production of myeloid cells to the detriment of lymphoid cells. Thus, the balance between these two lineages is disrupted in 4T1 tumor-bearing mice, creating an immunosuppressor phenotype that allows tumor growth. Among the myeloid cells produced, the myeloid-derived suppressor cells (MDSC) are produced in higher proportion in comparison to healthy animals. These MDSC cells are a heterogeneous population of immature myeloid cells that accumulate in lymphoid organs expands during cancer, inflammation, and infection, and has a remarkable ability to suppress T-cell responses. This study aimed to evaluate the presence of these MDSC cells after the treatment of 4T1-tumor-bearing mice with low-dose chemotherapy. We chose a low-dose treatment because some references showed that low-dose chemotherapy has the potential to reduce the number of immune suppressor cells to preferentially kill MDSCs that can be inhibited by Cyclophosphamide (CY) and 5-fluorouracil (5- FU). CY with 5-FU reduced breast cancer tumor growth and lung metastasis. In addition, lowdose therapy modified the number of leucocytes and phenotypes when compared to the positive control (tumor without treatment mice). Moreover, also observed the reduction of MDSC when compared to the positive control group. In conclusion, low-dose chemotherapy modified the leucocyte populations, and these modifications co-related with the systemic response to the therapy, including distant lung metastasis control.

BANKING MEMBERS:
Interna - 1677467 - DANIELA MARA DE OLIVEIRA
Presidente - 1929494 - JOAO PAULO FIGUEIRO LONGO
Externa ao Programa - 2171029 - MARIA DE FATIMA MENEZES ALMEIDA SANTOS