Microgravity research is an important part of space biology and human physiology, and has recently been used as a unique platform for drug discovery and cell therapy. Microgravity is a stress factor that disrupts cellular homeostasis, especially in the musculoskeletal, cardiovascular, immune and central nervous systems, as well as causing molecular and cellular changes. Both real and simulated microgravity can affect the survival and apoptosis of various cells and tissues. For instance, simulated microgravity can alter the chemo-responsiveness of cancer cells, potentially affecting cancer metastasis. Heat shock proteins (HSPs) can be used as biomarkers to assess cellular stress in cells and tissues exposed to microgravity, but our understanding of their role is still incomplete. To investigate the effects of microgravity on cells, we used a desktop random positioning machine (RPM) to simulate microgravity conditions. The flasks with cells in a static position were used as controls in the same incubator. Our previous studies have shown that simulated microgravity inhibits cell proliferation, induces apoptosis, and changes the morphology and expression of MEG-01 cell surface markers. We investigated the impact of microgravity on MEG-01 cells on drug treatment and found that microgravity amplifies cell sensitivity to drugs. Doxorubicin alone reduced cell viability and microgravity conditions amplified its effect. Cells treated with doxorubicin under microgravity showed a higher level of apoptosis (as measured by Annexin V staining). According to our data, the main changes in the expression of key apoptosis proteins in megakaryoblast cells under simulated microgravity conditions occurred after 96 hours. The expressions of BAX and cytochrome C proteins decreased under the influence of doxorubicin, with a more significant decrease under microgravity and with longer exposure times. This decrease in specific pro-apoptotic proteins contrasts with the increase in apoptosis, suggesting a complex regulation of cell death pathways. We found that treatment with doxorubicin under microgravity conditions resulted in increased HSP60 expression, in contrast to a decrease in HSP40 expression, relative to normal gravity. Our results are consistent with the study of apoptosis protein expression in different cells under simulated microgravity conditions. The microgravity-dependent modulation of cancer cells' response to chemotherapy has the potential to impact both space and terrestrial medicine. Biotechnology applications, facilitated by the use of cell and tissue cultures, will help us understand the adverse effects of gravity on health and aid in the preparation of space missions.