Effects of exogenous lactoferrin on phenotypic profile and invasiveness of human prostate cancer cells (DU145 and LNCaP) in vitro

Aim: To investigate the biological effects of exogenous lactoferrin (LF) on phenotypic profile and invasiveness of human prostate cancer (PC) cells in vitro. Materials and Methods: Human PC cell lines (LNCaP, DU-145) were cultured with an exogenous LF at a dose corresponding to IC30. The expression levels of steroid hormone receptors (androgen receptor, estrogen receptor, progesterone receptor), Her2/neu, Ki-67, E- and N-cadherin, were monitored by immunohistochemical analysis. The levels of miRNAs were assessed using q-PCR. The invasive activity of the cells was examined in a standard invasion test. Results: Exogenous LF reduced expression of steroid hormone receptors (ERα and PR) and Ki-67 in both PC cell lines. The expression of E-cadherin increased significantly in LF-treated DU-145 cells. Also, we established the decrease in invasive activity upon LF treatment by 40% and 30% in DU-145 and LNCaP cells, respectively. In DU-145 cells, incubation with exogenous LF resulted in an increase in the expression of oncosuppressive (miR-133a and miR-200b) miRNAs. Conclusions: Exogenous LF causes the changes in phenotypic characteristics of PC cells and levels of oncogenic and oncosuppressive miRNAs involved in the regulation of key cellular processes. Key Words: prostate cancer, exogenous lactoferrin, DU145, LNCaP, miRNA

Artemisinin modulating effect on human breast cancer cell lines with different sensitivity to cytostatics

Aim: To explore effects of Artemisinin on a series of breast cancer cells with different sensitivity to typical cytotoxic drugs (doxorubicin — Dox; cisplatin — DDP) and to investigate possible artemisinin-induced modification of the mechanisms of drug resistance. Materials and Methods: The study was performed on wild-type breast cancer MCF-7 cell line (MCF-7/S) and its two sublines MCF-7/Dox and MCF-7/DDP resistant to Dox and DDP, respectively. The cells were treated with artemisinin and iron-containing magnetic fluid. The latter was added to modulate iron levels in the cells and explore its role in artemisinin-induced effects. The MTT assay was used to monitor cell viability, whereas changes of expression of selected proteins participating in regulation of cellular iron homeostasis were estimated using immunocytochemical methods. Finally, relative expression levels of miRNA-200b, -320a, and -34a were examined by using qRT-PCR. Results: Artemisinin affects mechanisms of the resistance of breast cancer cells towards both Dox and DDP at sub-toxic doses. The former drug induces changes of expression of iron-regulating proteins via different mechanisms, including epigenetic regulation. Particularly, the disturbances in ferritin heavy chain 1, lactoferrin, hepcidin (decrease) and ferroportin (increase) expression (р ≤ 0.05) were established. The most enhanced increase of miRNA expression under artemisinin influence were found for miRNA-200b in MCF-7/DDP cells (7.1 ± 0.98 fold change), miRNA-320a in MCF-7/Dox cells (2.9 ± 0.45 fold change) and miRNA-34a (1.7 ± 0.15 fold change) in MCF-7/S cells. It was observed that the sensitivity to artemisinin can be influenced by changing iron levels in cells. Conclusions: Artemisinin can modify iron metabolism of breast cancer cells by its cytotoxic effect, but also by inducing changes in expression of iron-regulating proteins and microRNAs (miRNAs), involved in their regulation. This modification affects the mechanisms that are implicated in drug-resistance, that makes artemisinin a perspective modulator of cell sensitivity towards chemotherapeutic agents in cancer treatment

Modifying effects of 5-azacytidine on metal-containing proteins profile in guerin carcinoma with different sensitivity to cytostatics

Aim: To assess the influence of the treatment with 5-azacytidine (5-aza) on the profile of metal-containing proteins and factors of their regulation in Guerin carcinoma cells in vivo. Materials and Methods: The study was conducted on Wistar rats transplanted with wild-type Guerin carcinoma (Guerin/WT) and its strains resistant to cisplatin (Guerin/CP) or doxorubicin (Guerin/Dox). Animals were distributed in 6 groups treated with 5-aza and control animals without treatment. 5-Aza was injected by i.v. route (1 injection in 4 days at a dose of 2 mg/kg starting from the 4th day after tumor transplantation, 4 injections in total). Ferritin levels in blood serum and tumor tissue were measured by ELISA, transferrin and free iron complexes — by low-temperature EPR, miRNA-200b, -133a and -320a levels and promoter methylation — by real-time quantitative reverse transcription polymerase chain reaction. Results: The study has shown that 5-aza treatment caused demethylation of promoter regions of fth1 and tfr1 genes in all studied Guerin carcinoma strains. 5-Aza treatment resulted in a significant decrease of ferritin levels in tumor tissue (by 32.1% in Guerin/WT strain, by 29.8% in Guerin/Dox and by 69.1% in Guerin/CP). These events were accompanied by 3.5-fold and 2-fold increase of free iron complexes levels in tumor tissue of doxorubicin and cisplatin resistant strains, respectively. Also, 5-aza treatment resulted in significantly elevated levels of miR-200b, -133a, 320a expression in tumor tissue. After 5-aza treatment, ferritin levels in blood serum of animals with Guerin/Dox were increased by 23.9%, while in Guerin/Wt and Guerin/CP they were decreased by 17 and 16%, respectively. Conclusion: Alterations of epigenetic regulation upon in vivo treatment with 5-aza change the levels of metal-containing proteins due to DNA demethylation and altered miRNA expression profiles in Guerin carcinoma cells

EFFECTS OF EXOGENOUS LACTOFERRIN ON PHENOTYPIC PROFILE AND INVASIVENESS OF HUMAN PROSTATE CANCER CELLS (DU-145 AND LNCaP) IN VITRO

Aim: To investigate the biological effects of exogenous lactoferrin (LF) on phenotypic profile and invasiveness of human prostate cancer (PC) cells in vitro. Materials and Methods: Human PC cell lines (LNCaP, DU-145) were cultured with an exogenous LF at a dose corresponding to IC30. The expression levels of steroid hormone receptors (androgen receptor, estrogen receptor, progesterone receptor), Her2/neu, Ki-67, E- and N-cadherin, were monitored by immunohistochemical analysis. The levels of miRNAs were assessed using q-PCR. The invasive activity of the cells was examined in a standard invasion test. Results: Exogenous LF reduced expression of steroid hormone receptors (ERα and PR) and Ki-67 in both PC cell lines. The expression of E-cadherin increased significantly in LF-treated DU-145 cells. Also, we established the decrease in invasive activity upon LF treatment by 40% and 30% in DU-145 and LNCaP cells, respectively. In DU-145 cells, incubation with exogenous LF resulted in an increase in the expression of oncosuppressive (miR-133a and miR-200b) miRNAs. Conclusions: Exogenous LF causes the changes in phenotypic characteristics of PC cells and levels of oncogenic and oncosuppressive miRNAs involved in the regulation of key cellular processes. Key Words: prostate cancer, exogenous lactoferrin, DU145, LNCaP, miRNA

ARTEMISININ MODULATING EFFECT ON HUMAN BREAST CANCER CELL LINES WITH DIFFERENT SENSITIVITY TO CYTOSTATICS

Aim: To explore effects of Artemisinin on a series of breast cancer cells with different sensitivity to typical cytotoxic drugs (doxorubicin — Dox; cisplatin — DDP) and to investigate possible artemisinin-induced modification of the mechanisms of drug resistance. Materials and Methods: The study was performed on wild-type breast cancer MCF-7 cell line (MCF-7/S) and its two sublines MCF-7/Dox and MCF-7/DDP resistant to Dox and DDP, respectively. The cells were treated with artemisinin and iron-containing magnetic fluid. The latter was added to modulate iron levels in the cells and explore its role in artemisinin-induced effects. The MTT assay was used to monitor cell viability, whereas changes of expression of selected proteins participating in regulation of cellular iron homeostasis were estimated using immunocytochemical methods. Finally, relative expression levels of miRNA-200b, -320a, and -34a were examined by using qRT-PCR. Results: Artemisinin affects mechanisms of the resistance of breast cancer cells towards both Dox and DDP at sub-toxic doses. The former drug induces changes of expression of iron-regulating proteins via different mechanisms, including epigenetic regulation. Particularly, the disturbances in ferritin heavy chain 1, lactoferrin, hepcidin (decrease) and ferroportin (increase) expression (р ≤ 0.05) were established. The most enhanced increase of miRNA expression under artemisinin influence were found for miRNA-200b in MCF-7/DDP cells (7.1 ± 0.98 fold change), miRNA-320a in MCF-7/Dox cells (2.9 ± 0.45 fold change) and miRNA-34a (1.7 ± 0.15 fold change) in MCF-7/S cells. It was observed that the sensitivity to artemisinin can be influenced by changing iron levels in cells. Conclusions: Artemisinin can modify iron metabolism of breast cancer cells by its cytotoxic effect, but also by inducing changes in expression of iron-regulating proteins and microRNAs (miRNAs), involved in their regulation. This modification affects the mechanisms that are implicated in drug-resistance, that makes artemisinin a perspective modulator of cell sensitivity towards chemotherapeutic agents in cancer treatment

MODIFYING EFFECTS OF 5-AZACYTIDINE ON METAL-CONTAINING PROTEINS PROFILE IN GUERIN CARCINOMA WITH DIFFERENT SENSITIVITY TO CYTOSTATICS

Aim: To assess the influence of the treatment with 5-azacytidine (5-aza) on the profile of metal-containing proteins and factors of their regulation in Guerin carcinoma cells in vivo. Materials and Methods: The study was conducted on Wistar rats transplanted with wild-type Guerin carcinoma (Guerin/WT) and its strains resistant to cisplatin (Guerin/CP) or doxorubicin (Guerin/Dox). Animals were distributed in 6 groups treated with 5-aza and control animals without treatment. 5-Aza was injected by i.v. route (1 injection in 4 days at a dose of 2 mg/kg starting from the 4th day after tumor transplantation, 4 injections in total). Ferritin levels in blood serum and tumor tissue were measured by ELISA, transferrin and free iron complexes — by low-temperature EPR, miRNA-200b, -133a and -320a levels and promoter methylation — by real-time quantitative reverse transcription polymerase chain reaction. Results: The study has shown that 5-aza treatment caused demethylation of promoter regions of fth1 and tfr1 genes in all studied Guerin carcinoma strains. 5-Aza treatment resulted in a significant decrease of ferritin levels in tumor tissue (by 32.1% in Guerin/WT strain, by 29.8% in Guerin/Dox and by 69.1% in Guerin/CP). These events were accompanied by 3.5-fold and 2-fold increase of free iron complexes levels in tumor tissue of doxorubicin and cisplatin resistant strains, respectively. Also, 5-aza treatment resulted in significantly elevated levels of miR-200b, -133a, 320a expression in tumor tissue. After 5-aza treatment, ferritin levels in blood serum of animals with Guerin/Dox were increased by 23.9%, while in Guerin/Wt and Guerin/CP they were decreased by 17 and 16%, respectively. Conclusion: Alterations of epigenetic regulation upon in vivo treatment with 5-aza change the levels of metal-containing proteins due to DNA demethylation and altered miRNA expression profiles in Guerin carcinoma cells