New therapeutic targets in the treatment of prostate cancer

Development and In Vitro Evaluation of 2-Methoxyestradiol Loaded Polymeric Micelles for Enhancing Anticancer Activities in Prostate Cancer

The present study aimed to formulate and optimize 2ME-loaded PMs (2ME-PMs) for enhancing the anticancer activity of 2ME in prostate cancer (PC). The 2ME-PMs were formulated using PEG-PLGA (PL), Tween 80 (TW80), and alpha-lipoic acid (ALA). The optimization was carried out using a Box-Behnken design with the PL, TW80, and ALA as the independent variables and particle size (PS) as the response. The formulation was optimized for the lowest possible PS, and the software suggested optimum formula with 100.282 mg, 2%, and 40 mg for PL, TW80, and ALA, respectively. The optimized PMs had spherical morphology with PS of 65.36 ± 2.2 nm, polydispersity index (PDI) of 0.273 ± 0.03, and entrapment efficiency of 65.23 ± 3.5%. The in vitro drug release was 76.3 ± 3.2% after 24 h. The cell line studies using PC-3 cells showed IC50 values of 18.75 and 54.41 µmol for 2ME-PM and 2ME, respectively. The estimation of tumor biomarkers was also carried out. The tumor biomarkers caspase-9 (17.38 ± 1.42 ng/mL), tumor protein P53 (p53) (1050.0 ± 40.9 pg/mL), nitric oxide (NO) (0.693 ± 0.03 pg/mL), interleukin-1β (IL-1β) (25.84 ± 2.23 pg/mL), nuclear factor kappa B (NF-kB) (0.719 ± 0.07 pg/mL), interleukin-6 (IL-6) (2.53 ± 0.16 folds), and cyclooxygenase-2 (COX-2) (3.04 ± 0.5 folds) were determined for 2ME-PMs and the results showed that these values changed significantly compared to those of 2ME. Overall, the results showed that the formulation of 2ME to 2ME-PMs enhances the anticancer effect. The exploration of the combined advantages of PEG, PLGA, ALA, and PMs in cancer therapy and the delivery of 2ME is the major importance of this research work. PEG reduces the elimination of 2ME, PLGA enhances 2ME loading, ALA has an inherent apoptotic effect, and PMs can efficiently target tumor cells.

Retinoic Acid and Its Derivatives in Skin

The retinoids are a group of compounds including vitamin A and its active metabolite all-trans-retinoic acid (ATRA). Retinoids regulate a variety of physiological functions in multiple organ systems, are essential for normal immune competence, and are involved in the regulation of cell growth and differentiation. Vitamin A derivatives have held promise in cancer treatment and ATRA is used in differentiation therapy of acute promyelocytic leukemia (APL). ATRA and other retinoids have also been successfully applied in a variety of dermatological conditions such as skin cancer, psoriasis, acne, and ichthyosis. Moreover, modulation of retinoic acid receptors and retinoid X (or rexinoid) receptors function may affect dermal cells. The studies using complex genetic models with various combinations of retinoic acid receptors (RARs) and retinoid X (or rexinoid) receptors (RXRs) indicate that retinoic acid and its derivatives have therapeutic potential for a variety of serious dermatological disorders including some malignant conditions. Here, we provide a synopsis of the main advances in understanding the role of ATRA and its receptors in dermatology.

Anti-cancer effect of bee venom in prostate cancer cells through activation of caspase pathway via inactivation of NF-κB

BACKGROUND

Bee venom has been used as a traditional medicine to treat arthritis, rheumatism, back pain, cancerous tumors, and skin diseases. However, the effects of bee venom on the prostate cancer and their action mechanisms have not been reported yet.

METHODS

To determine the effect of bee venom and its major component, melittin on the prostate cancer cells, apoptosis is analyzed by tunnel assay and apoptotic gene expression. For xenograft studies, bee venom was administrated intraperitoneally twice per week for 4 weeks, and the tumor growth was measured and the tumor were analyzed by immunohistochemistry. To investigate whether bee venom and melittin can inactivate nuclear factor kappa B (NF-κB), we assessed NF-κB activity in vitro and in vivo.

RESULTS AND CONCLUSIONS

Bee venom (1-10 µg/ml) and melittin (0.5-2.5 µg/ml) inhibited cancer cell growth through induction of apoptotic cell death in LNCaP, DU145, and PC-3 human prostate cancer cells. These effects were mediated by the suppression of constitutively activated NF-κB. Bee venom and melittin decreased anti-apoptotic proteins but induced pro-apoptotic proteins. However, pan caspase inhibitor abolished bee venom and melittin-induced apoptotic cell death and NF-κB inactivation. Bee venom (3-6 mg/kg) administration to nude mice implanted with PC-3 cells resulted in inhibition of tumor growth and activity of NF-κB accompanied with apoptotic cell death. Therefore, these results indicated that bee venom and melittin could inhibit prostate cancer in in vitro and in vivo, and these effects may be related to NF-κB/caspase signal mediated induction of apoptotic cell death.