[Involvement of PI3K/Akt pathway in prostate cancer. Potential strategies for developing targeted therapies]

Biomaterial-based in vitro 3D modeling of glioblastoma multiforme

Adult-onset brain cancers, such as glioblastomas, are particularly lethal. People with glioblastoma multiforme (GBM) do not anticipate living for more than 15 months if there is no cure. The results of conventional treatments over the past 20 years have been underwhelming. Tumor aggressiveness, location, and lack of systemic therapies that can penetrate the blood-brain barrier are all contributing factors. For GBM treatments that appear promising in preclinical studies, there is a considerable rate of failure in phase I and II clinical trials. Unfortunately, access becomes impossible due to the intricate architecture of tumors. In vitro, bioengineered cancer models are currently being used by researchers to study disease development, test novel therapies, and advance specialized medications. Many different techniques for creating in vitro systems have arisen over the past few decades due to developments in cellular and tissue engineering. Later-stage research may yield better results if in vitro models that resemble brain tissue and the blood-brain barrier are used. With the use of 3D preclinical models made available by biomaterials, researchers have discovered that it is possible to overcome these limitations. Innovative in vitro models for the treatment of GBM are possible using biomaterials and novel drug carriers. This review discusses the benefits and drawbacks of 3D in vitro glioblastoma modeling systems.

Design, synthesis and pharmacological evaluation of 2-arylurea-1,3,5-triazine derivative (XIN-9): A novel potent dual PI3K/mTOR inhibitor for cancer therapy

Blocking the PI3K/AKT/mTOR pathway has been widely recognized as an attractive cancer therapeutic strategy because of its crucial role in cell growth and survival. In this study, a novel series of 2-arylurea-1,3,5-triazine derivatives had been synthesized and evaluated as highly potent PI3K and mTOR inhibitors. The new compounds exhibited cytotoxic activities against MCF-7, Hela and A549 cancer cell lines (IC₅₀ = 0.03-36.54 μM). The most promising compound XIN-9 exhibited potent inhibition against PI3K and mTOR kinase (IC₅₀ = 23.8 and 10.9 nM). Mechanistic study using real-time PCR revealed the ability of XIN-9 to inhibit PI3K and mTOR. In addition, compound XIN-9 arrested the cell cycle of MCF-7 cells at the G0/G1 phase. XIN-9 also caused a significant dose-dependent increase of early and late apoptotic events. Molecular docking analysis revealed a high binding affinity for XIN-9 toward PI3K and mTOR. Following in vitro studies, XIN-9 was further evaluated in MCF-7 xenograft models to show significant in vivo anticancer efficacies with tumor growth inhibitions of 41.67% (po, 75 mg/kg). Overall, this work indicated that compound XIN-9 represents a potential anticancer targeting PI3K/AKT/mTOR pathway.

Homeobox protein VentX induces p53-independent apoptosis in cancer cells

Identifying novel tumor suppressors holds promise for improving cancer treatment. Our recent studies identified VentX, a homeobox transcriptional factor, as a putative tumor suppressor. Here we demonstrate that VentX exerts strong inhibitory effects on the proliferation and survival of cancer cells, but not primary transformed cells, such as 293T cells. Mechanistically, both in vitro and in vivo data showed that VentX induces apoptosis of cancer cells in a p53-independent manner. We found that VentX expression can be induced by chemotherapeutic agents. Taken together, our findings suggest that VentX may function as a novel therapeutic target in cancer treatment.

Murine prostate cancer inhibition by dietary phytochemicals--curcumin and phenyethylisothiocyanate

PURPOSE

Prior studies from our laboratory have demonstrated the efficacy of a combined treatment of low doses of dietary agents curcumin and phenylethylisothiocyanate in effectively suppressing prostate cancer in vitro in human prostate cancer PC3 cells as well as in vivo in immunodeficient mice implanted with PC3 cells. Hence, this study was undertaken to examine the potential chemopreventive properties of the two agents against transgenic adenocarcinoma of the mouse prostate.

MATERIALS AND METHODS

The efficacy of AIN-76A diet supplemented with 2% curcumin or 0.05% PEITC or a combination of 1% curcumin and 0.025% PEITC for periods of 10 and 16 weeks was tested against adenocarcinoma of the mouse prostate. Immunohistochemistry and Western blot analysis were used to examine the expression of proliferation and apoptotic biomarkers. All statistical tests were two-sided.

RESULTS

Supplementing AIN-76A diet with dietary phytochemicals curcumin or PEITC either alone or in combination, significantly decreased incidence of prostate tumor formation (P = 0.0064). Immunohistochemistry revealed a significant inhibition of high-grade PIN (P = 0.0006, 0.000069, 0.00029 for a treatment period of 10 weeks and P = 0.02582, 0.022179, 0.0317 for a treatment period of 16 weeks) along with decreased proliferation and increased apoptotic index in the curcumin, PEITC or curcumin and PEITC treated animals, respectively. Furthermore, Western blot analysis revealed that downregulation of the Akt signaling pathway may in part play a role in decreasing cell proliferation ultimately retarding prostate tumor formation.

CONCLUSION

Our data lucidly evidence the chemopreventive merits of dietary phytochemicals curcumin and PEITC in suppressing prostate adenocarcinoma.