tolfenamic-acid and Prostatic-Neoplasms

Specificity protein (Sp) transcription factors are implicated in critical cellular and molecular processes associated with cancer that impact tumor growth and metastasis. The non-steroidal anti-inflammatory drug, tolfenamic acid (TA) is known to inhibit Sp proteins in some human cancer cells and laboratory animal models. We evaluated the anti-cancer activity of TA using in vitro and in vivo models for prostate cancer.. The anti-proliferative efficacy of TA was evaluated using DU-145, PC-3, and LNCaP cells. PC-3 cells were treated with DMSO or 50 µM TA for 48 hr. Whole cell lysates were evaluated for the expression of Sp1, survivin, c-PARP, Akt/p-Akt, c-Met, cdk4, cdc2, cyclin D3, and E2F1 by Western blot analysis. Cell invasion was assessed by Boyden-chamber assay and flow cytometry analysis was used to study apoptosis and cell cycle distribution. An orthotopic mouse model for prostate cancer with PC-3-Luc cells was used to study the in vivo effect of TA.. TA inhibited the expression of Sp1, c-Met, p-Akt, and survivin; increased c-PARP expression and caspases activity in PC-3 cells. TA caused cell arrest at G(0) /G(1) phase accompanied by a decrease in cdk4, cdc2, cyclin D3, and E2F1 and an increase in critical apoptotic markers. TA augmented annexin-V staining, caspase activity, and c-PARP expression indicating the activation of apoptotic pathways. TA also decreased PC-3 cell invasion. TA significantly decreased the tumor weight and volume which was associated with low expression of Sp1 and survivin in tumor sections.. TA targets critical pathways associated with tumorigenesis and invasion. These pre-clinical data strongly demonstrated the anti-cancer activity of TA in prostate cancer.

Topics: Adenocarcinoma; Animals; Anti-Inflammatory Agents, Non-Steroidal; Antineoplastic Agents; Apoptosis; Biomarkers, Tumor; Cell Adhesion; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cell Survival; Male; Mice; Mice, Nude; Neoplasm Invasiveness; ortho-Aminobenzoates; Prostatic Neoplasms; Xenograft Model Antitumor Assays

Tolfenamic acid (Tol) is a non-steroidal anti-inflammatory drug that was reported to exhibit anticancer activity in pancreatic and colorectal cancer models. This study examined the role of Tol in the death regulation of PC-3 and DU145 human androgen-independent prostate cancer cells. The results showed that Tol inhibited cell growth and induced apoptosis, as evidenced by nuclear fragmentation and cleaved caspase 3 and poly(ADP-ribose) polymerase. Tol suppressed the specificity protein 1 (Sp1) protein in both PC-3 and DU145 cells. Tol also attenuated Sp1 mRNA and its promoter activity in DU145 cells, but did not alter them in PC-3 cells, indicating that Tol degrades Sp1 protein in these cells. Tol also downregulated protein levels, mRNA levels and promoter activities of survivin and myeloid cell leukemia-1, which are downstream targets of Sp1. The expressions of survivin and Mcl-1 and cancer cell growth were lower in the PC-3 cells treated with Sp1 interfering RNA and mithramycin A. Moreover, an oral injection of Tol decreased tumor growth and downregulated the Sp1 protein in athymic nude mice bearing DU145 cell xenografts without hepatotoxicity. Overall, Tol downregulates the Sp1 protein to inhibit growth and induce apoptosis in androgen-refractory prostate cancers, both in vitro and in vivo, that show resistance against many chemotherapeutic agents.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Apoptosis; Blotting, Western; Caspase 3; Cell Cycle; Cell Proliferation; Down-Regulation; Humans; Immunoenzyme Techniques; Luciferases; Male; Mice; Mice, Nude; Neoplasms, Hormone-Dependent; ortho-Aminobenzoates; Prostatic Neoplasms; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Sp1 Transcription Factor; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

The androgen receptor (AR), which mediates the signals of androgens, plays a crucial role in prostate-related diseases. Although widely used, currently marketed anti-androgenic drugs have significant side effects. Several studies have revealed that non-steroidal anti-inflammatory drugs, such as flufenamic acid, block AR transcriptional activity. Herein we describe the development of small molecule analogues of flufenamic acid that antagonize AR. This novel class of AR inhibitors binds to the hormone binding site, blocks AR transcription activity, and acts on AR target genes.

Topics: Androgen Receptor Antagonists; Antineoplastic Agents; Antineoplastic Agents, Hormonal; Cell Line, Tumor; Flufenamic Acid; Gene Expression Regulation, Neoplastic; Humans; Male; Prostatic Neoplasms; Receptors, Androgen; Structure-Activity Relationship; Tacrolimus Binding Proteins; Transcriptional Activation