Ovarian cancer is the leading cause of death among gynaecological malignancies. Multiple drug resistance makes cancer cells insensitive to chemotherapy. In this study, we developed six primary ovarian cancer cell lines (W1MR, W1CR, W1DR, W1VR, W1TR, and W1PR) resistant to drugs such as methotrexate, cisplatin, doxorubicin, vincristine, topotecan, and paclitaxel. A chemosensitivity assay MTT test was performed to assess drug cross-resistance. Quantitative real-time polymerase chain reaction and Western blot were also performed to determine mRNA and protein expression of genes involved in chemoresistance. We observed high cross-resistance to doxorubicin, vincristine, and paclitaxel in the cell lines resistant to these agents. We also found a significant correlation between resistance to these drugs and increased expression of P-gp. Two different mechanisms of topotecan resistance were observed in the W1TR and W1PR cell lines. We did not observe any correlation between MRP2 transcript and protein levels. Cell lines resistant to agents used in ovarian cancer treatment remained sensitive to methotrexate. The main mechanisms of drug resistance were due to P-gp expression in the doxorubicin, vincristine, and paclitaxel resistant cell lines and BCRP expression in the topotecan resistant cell line.

DiO and DiD are lipophilic cell labelling dyes used in the staining of cells in vivo and in vitro. The aim of the present study was to quantify the asymmetrical distribution of dyes in co‑cultured cells and to measure the intercellular transfer of DiO and DiD. DiO and DiD were applied separately to stain two identical populations of SW‑1353 human chondrosarcoma cells that were subsequently co‑cultured (homotypic co‑culture). The intercellular migration of dyes in the co‑cultured cells was measured by flow cytometry and recorded under a fluorescent microscope. DiD and DiO caused no effect on the proliferation of cells, the degradation rate of the two dyes was comparable and crossover effects between dyes were negligible. The results of the present study suggested that asymmetrical intercellular migration of DiD and DiO was responsible for the asymmetrical distribution of these dyes in co‑cultured cells. To take advantage of the lipophilic dyes migration in the double-stained co-cultured cells we suggest to apply mixed-dyes controls prior to the flow cytometric analysis. These controls are performed by staining cells with a 1:1 mix of the two dyes and would enable the estimation of the intensity of intercellular contact in co‑culture systems. A 1:1 premix of DiO and DiD was applied to estimate cellular effect on intercellular exchange of lipid dyes in co‑cultures incubated with cycloheximide and cytochalasin B. The cellular effect contributed 6‑7% of intercellular migration of the lipophilic dyes, DiO and DiD. The majority of the observed intercellular transfer of these dyes was due to non‑cellular, passive transfer.

The growth and development of oocyte affect the functional activities of the surrounding somatic cells. These cells are regulated by various types of hormones, proteins, metabolites, and regulatory molecules through gap communication, ultimately leading to the development and maturation of oocytes. The close association between somatic cells and oocytes, which together form the cumulus-oocyte complexes (COCs), and their bi-directional communication are crucial for the acquisition of developmental competences by the oocyte. In this study, oocytes were extracted from the ovaries obtained from crossbred landrace gilts and subjected to in vitro maturation. RNA isolated from those oocytes was used for the subsequent microarray analysis. The data obtained shows, for the first time, variable levels of gene expression (fold changes higher than |2| and adjusted p-value < 0.05) belonging to four ontological groups: regulation of cell proliferation (GO:0042127), regulation of cell migration (GO:0030334), and regulation of programmed cell death (GO:0043067) that can be used together as proliferation, migration or apoptosis markers. We have identified several genes of porcine oocytes (ID2, VEGFA, BTG2, ESR1, CCND2, EDNRA, ANGPTL4, TGFBR3, GJA1, LAMA2, KIT, TPM1, VCP, GRID2, MEF2C, RPS3A, PLD1, BTG3, CD47, MITF), whose expression after in vitro maturation (IVM) is downregulated with different degrees. Our results may be helpful in further elucidating the molecular basis and functional significance of a number of gene markers associated with the processes of migration, proliferation and angiogenesis occurring in COCs.

Nowadays, science has a lot of knowledge about the physiology of ovarian processes, especially folliculogenesis, hormone production and ovulation. However, the molecular basis for these processes remains largely undiscovered. The cell layer surrounding the growing oocyte—granulosa cells—are characterized by high physiological capabilities (e.g., proliferation, differentiation) and potential for growth in primary cultures, which predisposes them for analysis in the context of possible application of their cultures in advanced methods of assisted reproduction. In this study, we have used standard molecular approaches to analyze markers of these processes in primarily in vitro cultured porcine granulosa, subjected to conditions usually applied to cultures of similar cells. The material for our research came from commercially slaughtered pigs. The cells were obtained by enzymatic digestion of tissues and in vitro culture in appropriate conditions. The obtained genetic material (RNA) was collected at specific time intervals (0 h—before culture; reference, 48, 98, 144 h) and then analyzed using expression microarrays. Genes that showed a fold change greater than |2| and an adjusted p value lower than 0.05 were described as differentially expressed. Three groups of genes: “Cell morphogenesis”, “cell differentiation” and “cell development” were analyzed. From 265 differently expressed genes that belong to chosen ontology groups we have selected DAPL1, CXCL10, NEBL, IHH, TGFBR3, SCUBE1, DAB1, ITM2A, MCOLN3, IGF1 which are most downregulated and PDPN, CAV1, TMOD1, TAGLN, IGFBP5, ITGB3, LAMB1, FN1, ITGA2, POSTN genes whose expression is upregulated through the time of culture, on which we focused in downstream analysis. The results were also validated using RT-qPCR. The aim of our work was to conduct primary in vitro culture of granulosa cells, as well as to analyze the expression of gene groups in relation to the proliferation of follicular granulosa cells in the model of primary culture in real time. This knowledge should provide us with a molecular insight into the processes occurring during the in vitro cultures of porcine granulosa cells, serving as a basic molecular entry on the extent of the loss of their physiological properties, as well as gain of new, culture-specific traits.

Degeneration of the intervertebral disc (IVD) is the main cause of age-related damage of spinal tissues. Using multipotent mesenchymal stromal cells (MSCs) regenerative medicine intends to restore the IVD components of annulus fibrosus (AF) and nucleus pulposus (NP). In the present study NP cells (NPCs) and MSCs obtained from adolescent patients suffering from scoliosis were used. IVDs and vertebrae were obtained during surgery and subsequently processed in order to establish cultures of NPCs and MSCs. The two cell types were co-cultured in 1-µm pore size insert system (indirect co-culture) or on one surface (direct co-culture). Prior to co-culture in these systems one of the cell types was stained by lipophilic fluorescent dye DiD (red). The results demonstrated that regardless of the cell type, the flow of DiD from stained to non-stained cells was more efficient in the direct co-culture in comparison with the insert system. Moreover, in the direct system the DiD flow was more efficient from MSCs towards NPCs compared with that in the opposite direction. These data indicated that the membrane interchange between the two cell types was asymmetric. To discriminate the subpopulation of cells that underwent membrane interchange, cells were double stained with DiD and DiO (green). In the first part of the experiment NPCs were stained by DiO and MSCs by DiD. In the second, NPCs were stained by DiD and MSCs by DiO. The cells were co-cultured in the direct system for 8 days and subsequently analyzed by flow cytometry and confocal microscopy. This analysis revealed that >50% of cells were stained by the DiO and DiD dyes. NPCs and MSCs formed structures similar to tunnelling nanotubes (TnT). In conclusion, the formation of TnT-like structures is able to promote, phenotypic changes during the direct co-culture of NPCs with MSCs.