Three candidate anticancer drugs were repositioned by integrative analysis of the transcriptomes of species with different regenerative abilities after injury.

Regeneration is a homeostatic process that involves the restoration of cells and body parts. Most of the molecular mechanisms and signalling pathways involved in wound healing, such as proliferation, have also been associated with cancer cell growth, suggesting that cancer is an over/unhealed wound. In this study, we examined differentially expressed genes in spinal cord samples from regenerative organisms (axolotl and zebrafish) and nonregenerative organisms (mouse and rat) compared to intact control spinal cord samples using publicly available transcriptomics data and bioinformatics analyses. Based on these gene signatures, we investigated 3 small compounds, namely cucurbitacin I, BMS-754807, and PHA-793887 as potential candidates for the treatment of cancer. The predicted target genes of the repositioned compounds were mainly enriched with the greatest number of genes in cancer pathways. The molecular docking results on the binding affinity between the repositioned compounds and their target genes are also reported. The repositioned 3 small compounds showed anticancer effect both in 2D and 3D cell cultures using the prostate cancer cell line as a model. We propose cucurbitacin I, BMS-754807, and PHA-793887 as potential anticancer drug candidates. Future studies on the mechanisms associated with the revealed gene signatures and anticancer effects of these three small compunds would allow scientists to develop therapeutic approaches to combat cancer. This research contributes to the evaluation of mechanisms and gene signatures that either limit or cause cancer, and to the development of new cancer therapies by establishing a link between regeneration and carcinogenesis.

Investigation of the cytotoxic, anti-proliferative and anti-angiogenic effects of Toluhydroquinone on Caco-2 cell line.

Colorectal cancer is one of the most common types of cancer in the world. The treatment options for colorectal carcinoma generally consist of surgery, radiotherapy and chemotherapy. The drug resistance to chemotherapy agents used in the current cancer treatment has brought about the finding of new drug molecules from some plant and aquatic species in the treatment approaches. Some species of aquatic biota create novel biomolecules as potential drugs for cancer and other diseases. Toluhydroquinone belongs to these groups of biomolecules and it shows anti-oxidative, anti-inflammatory and anti-angiogenic properties. In this study, we tested the cytotoxic and anti-angiogenic effects of Toluhydroquinone on Caco-2(Human colorectal carcinoma cell line) cells. It was observed that the amount of closure of the wound space, colony forming ability (in vitro cell survivability) and formation of tubule-like structures in matrigel decreased in comparison to the control group. As a result of this study, Toluhydroquinone has cytotoxic, anti-proliferative and anti-angiogenic properties on the Caco-2 cell line.

YAP1 Is Involved in Tumorigenic Properties of Prostate Cancer Cells.

The Yes Associated Protein 1 (YAP1) is a transcriptional cofactor negatively regulated by Hippo Pathway. The dysregulation of the pathway has been shown to have a role in tumorigenesis and metastasis in several cancers including prostate cancer (PCa). In this study, YAP1 expression was upregulated in the whole cell lysates and cytoplasmic/nuclear extracts of AR negative (PC3) compared to AR positive (LNCaP) prostate cancer cell lines and primary prostate epithelial cells (PrePEC). pYAP1 expression elevated in LNCaP compared to PC3 and PrePEC in whole cell lysates and cytoplasmic extracts. The treatment of LNCaP and PC3 with YAP1-targeting siRNA oligonucleotides (YAP1 siRNA) significantly reduced their proliferation in vitro. Furthermore, treatment with YAP1 siRNA diminished the clonogenicity, anchorage-independent growth on soft agar, migration and invasion of PC3 cells. Co-IP/WB experiments revealed that YAP1 and AR formed a complex and ChIP/PCR results confirmed that YAP1 was bound to androgen response elements (ARE) core region of the prostate specific antigen (PSA) promoter. The loss of function experiments in LNCaP and PC3 revealed that YAP1 regulates proliferation, colony formation as well as anchorage-independent growth and potentially plays an important role in migration and invasion. Finally, analysis of publicly available data sets indicated that LNCaP had no YAP1 copy number alteration whereas PC3 had gain of YAP1 which was also reflected as an increase in the mRNA level. Moreover, YAP1 copy number gain and elevated YAP1 mRNA expression were detected in clinical samples analyzed in publicly available data sets. Taken together, these results suggested that YAP1 has a role in PCa tumorigenesis.

Increased expression of YAP1 in prostate cancer correlates with extraprostatic extension.

OBJECTIVE: Yes associated protein 1 (YAP1) is a member of the Hippo pathway, acting as a transcriptional coactivator. To elucidate the role of YAP1 and phosphorylated (p)YAP1 in prostate cancer (PCa) tumorigenesis, we investigated their expression in clinical samples of PCa and cell lines. METHODS: Fifty-four tumor, adjacent nontumor, and prostate intraepithelial neoplasia (PIN) tissues from patients with PCa after radical prostatectomy were selected from a retrospective cohort and studied using immunohistochemistry (IHC). Protein and mRNA expression levels of YAP1 were evaluated by Western blot analysis and quantitative real-time reverse transcription PCR, respectively, in cancer cell lines. Publicly available gene expression datasets were downloaded to analyze YAP1 mRNA and protein levels in PCa tissue samples. RESULTS: IHC analysis of PCa tissues revealed that YAP1 staining intensities were moderate to weak in the nucleus and cytoplasm of tumor cells, whereas adjacent normal epithelia showed strong staining. We observed that benign prostates were characterized by higher expression levels of both nuclear (P=0.004) and cytosolic (P=0.005) YAP1. pYAP1 staining was weak in the cytoplasm and absent in the nucleus of all the tissues investigated. YAP1 expression was an indicator of extraprostatic extension (EPE). The level of YAP1 was negatively correlated with the level of the androgen receptor (AR) in The Cancer Genome Atlas dataset and Western blot analysis of cell lines. CONCLUSIONS: Our study suggested that YAP1 expression is heterogeneous in PCa tissue samples; therefore, YAP1 might play different roles in different aspects of PCa progression. This might involve AR-YAP1 interplay in PCa.

A hormone-dependent feedback-loop controls androgen receptor levels by limiting MID1, a novel translation enhancer and promoter of oncogenic signaling.

BACKGROUND: High androgen receptor (AR) level in primary tumour predicts increased prostate cancer (PCa)-specific mortality. Furthermore, activations of the AR, PI3K, mTOR, NFκB and Hedgehog (Hh) signaling pathways are involved in the fatal development of castration-resistant prostate cancer during androgen ablation therapy. MID1, a negative regulator of the tumor-suppressor PP2A, is known to promote PI3K, mTOR, NFκB and Hh signaling. Here we investigate the interaction of MID1 and AR. METHODS: AR and MID1 mRNA and protein levels were measured by qPCR, Western blot and immunohistochemistry. Co-immunoprecipitation followed by PCR and RNA-pull-down followed by Western blot was used to investigate protein-mRNA interaction, chromatin-immunoprecipitation followed by next-generation sequencing for identification of AR chromatin binding sites. AR transcriptional activity and activity of promoter binding sites for AR were analyzed by reporter gene assays. For knockdown or overexpression of proteins of interest prostate cancer cells were transfected with siRNA or expression plasmids, respectively. RESULTS: The microtubule-associated MID1 protein complex associates with AR mRNA via purine-rich trinucleotide repeats, expansions of which are known to correlate with ataxia and cancer. The level of MID1 directly correlates with the AR protein level in PCa cells. Overexpression of MID1 results in a several fold increase in AR protein and activity without major changes in mRNA-levels, whereas siRNA-triggered knockdown of MID1 mRNA reduces AR-protein levels significantly. Upregulation of AR protein by MID1 occurs via increased translation as no major changes in AR protein stability could be observed. AR on the other hand, regulates MID1 via several functional AR binding sites in the MID1 gene, and, in the presence of androgens, exerts a negative feedback loop on MID1 transcription. Thus, androgen withdrawal increases MID1 and concomitantly AR-protein levels. In line with this, MID1 is significantly over-expressed in PCa in a stage-dependent manner. CONCLUSION: Promotion of AR, in addition to enhancement of the Akt-, NFκB-, and Hh-pathways by sustained MID1-upregulation during androgen deprivation therapy provides a powerful proliferative scenario for PCa progression into castration resistance. Thus MID1 represents a novel, multi-faceted player in PCa and a promising target to treat castration resistant prostate cancer.

Metformin anti-tumor effect via disruption of the MID1 translational regulator complex and AR downregulation in prostate cancer cells.

BACKGROUND: Metformin is an approved drug prescribed for diabetes. Its role as an anti-cancer agent has drawn significant attention because of its minimal side effects and low cost. However, its mechanism of anti-tumour action has not yet been fully clarified. METHODS: The effect on cell growth was assessed by cell counting. Western blot was used for analysis of protein levels, Boyden chamber assays for analyses of cell migration and co-immunoprecipitation (CoIP) followed by western blot, PCR or qPCR for analysis of protein-protein and protein-mRNA interactions. RESULTS: Metformin showed an anti-proliferative effect on a wide range of prostate cancer cells. It disrupted the AR translational MID1 regulator complex leading to release of the associated AR mRNA and subsequently to downregulation of AR protein in AR positive cell lines. Inhibition of AR positive and negative prostate cancer cells by metformin suggests involvement of additional targets. The inhibitory effect of metformin was mimicked by disruption of the MID1-α4/PP2A protein complex by siRNA knockdown of MID1 or α4 whereas AMPK activation was not required. CONCLUSIONS: Findings reported herein uncover a mechanism for the anti-tumor activity of metformin in prostate cancer, which is independent of its anti-diabetic effects. These data provide a rationale for the use of metformin in the treatment of hormone naïve and castration-resistant prostate cancer and suggest AR is an important indirect target of metformin.