1-methylnicotinamide and its structural analog 1,4-dimethylpyridine for the prevention of cancer metastasis

Background: 1-methylnicotinamide (1-MNA), an endogenous metabolite of nicotinamide, has recently gained interest due to its anti-inflammatory and anti-thrombotic activities linked to the COX-2/PGI2 pathway. Given the previously reported anti-metastatic activity of prostacyclin (PGI2), we aimed to assess the effects of 1-MNA and its structurally related analog, 1,4-dimethylpyridine (1,4-DMP), in the prevention of cancer metastasis. Methods: All the studies on the anti-tumor and anti-metastatic activity of 1-MNA and 1,4-DMP were conducted using the model of murine mammary gland cancer (4T1) transplanted either orthotopically or intravenously into female BALB/c mouse. Additionally, the effect of the investigated molecules on cancer cell-induced angiogenesis was estimated using the matrigel plug assay utilizing 4T1 cells as a source of pro-angiogenic factors. Results: Neither 1-MNA nor 1,4-DMP, when given in a monotherapy of metastatic cancer, influenced the growth of 4T1 primary tumors transplanted orthotopically; however, both compounds tended to inhibit 4T1 metastases formation in lungs of mice that were orthotopically or intravenously inoculated with 4T1 or 4T1-luc2-tdTomato cells, respectively. Additionally, while 1-MNA enhanced tumor vasculature formation and markedly increased PGI2 generation, 1,4-DMP did not have such an effect. The anti-metastatic activity of 1-MNA and 1,4-DMP was further confirmed when both agents were applied with a cytostatic drug in a combined treatment of 4T1 murine mammary gland cancer what resulted in up to 80 % diminution of lung metastases formation. Conclusions: The results of the studies presented below indicate that 1-MNA and its structural analog 1,4-DMP prevent metastasis and might be beneficially implemented into the treatment of metastatic breast cancer to ensure a comprehensive strategy of metastasis control

Effects of antidepressants on GluR2 Q/R site-RNA editing in modified HeLa cell line.

http://dx.doi.org/10.1016/j.neures.2009.03.009 authorMarked reduction of RNA editing at the glutamine (Q)/arginine (R) site of the glutamate receptor subunit type 2 (GluR2) in motor neurons may be a contributory cause of neuronal death specifically in sporadic ALS. It has been shown that deregulation of RNA editing of several mRNAs plays a causative role in diseases of the central nervous system such as depression. We analyzed the effects of eight antidepressants on GluR2 Q/R site-RNA editing in a modified HeLa cell line that stably expresses half-edited GluR2 pre-mRNA. We also measured changes in RNA expression levels of adenosine deaminase acting on RNA type 2 (ADAR2), the specific RNA editing enzyme of the GluR2 Q/R site, and GluR2, in order to assess the molecular mechanism causing alteration of this site-editing. The editing efficiency at the GluR2 Q/R site was significantly increased after treatment with seven out of eight antidepressants at a concentration of no more than 10 μM for 24 h. The relative abundance of ADAR2 mRNA to GluR2 pre-mRNA or to β-actin mRNA was increased after treatment with six of the effective antidepressants, whereas it was unchanged after treatment with milnacipran. Our results suggest that antidepressants have the potency to enhance GluR2 Q/R site-editing by either upregulating the ADAR2 mRNA expression level or other unidentified mechanisms. It may be worth investigating the in vivo efficacy of antidepressants with a specific therapeutic strategy for sporadic ALS in view