Background: Hepatocellular carcinoma (HCC) is the most common form of liver cancer that occurs in hepatocytes. Although many chemical drugs, e.g., cisplatin, methotrexate, taxis, and doxorubicin are used to treat HCC, there have been numerous reports related to the side effects of these drugs (e.g., emerging drug resistance, bone marrow failure, and gastrointestinal disorders). These issues led scientists to search for the novel anti-cancer drugs, mainly in natural products with greater efficiency and less toxicity. The current survey was intended to assess the anti-cancer effects of queen bee acid (10-Hydroxy-2-Decenoic Acid, 10-HDA) and its cellular mechanisms against the human hepatoma cell line HepG2. Materials and Methods: The MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay was used to evaluate the effect of 10-HDA on the viability of HepG2 cells. The initial and late apoptosis in the HepG2 cells treated with 10-HDA were assessed by the Annexin-V (AV) assay. The level of the gene and protein expression of some apoptosis genes (e.g., caspase-3, Bcl-2-associated X protein (BAX), and B-cell lymphoma protein 2 (Bcl-2)), Poly (ADP-ribose) polymerases (PARP), and miRNA-34a (miR-34a), were measured by real-time PCR and Western blot. Results: The obtained findings revealed that HepG2 cell viability was markedly reduced (p < 0.01) following exposure to 10-HDA in a dose-dependent matter. The calculated half maximal cytotoxic concentration (CC50) value of 10-HDA was 59.6 µg/mL for HepG2 cells, while this value for normal THLE-3 cells was 106.4 µg/mL. We found that 10-HDA markedly elevated (p < 0.01) the percentage of necrotic and apoptotic cells from 0.94 to 9.7 and 27.6%, respectively. The real-time PCR results showed that the expression levels of the caspase-3, Bax, and miR-34a genes were significantly (p < 0.001) elevated. Contrary to these results, a significant (p < 0.01) reduction in the expression level of the Bcl2 gene was observed. The levels of protein expression of Caspase-3, PARP, and Bax were markedly elevated following exposure of HepG2 cells to 10-HDA at ¼ CC50, ½ CC50, and CC50. The level of protein expression of Bcl-2 was markedly reduced following exposure of HepG2 cells to 10-HDA at ¼ CC50, ½ CC50, and CC50 (p < 0.01). Conclusion: The current results confirmed the potent in vitro cytotoxic effects of 10-HDA on HepG2 cells with no significant cytotoxic effects on normal cells. Although its mechanisms of action have not been fully studied, the induction of apoptosis via different pathways was determined as one of the principle mechanisms of action of 10-HDA against HepG2 cells. Nevertheless, additional surveys must be performed to clearly understand the mechanisms of action and safety of this fatty acid. Full article

Polyamine (PA) catabolism is often reduced in cancer cells. The activation of this metabolic pathway produces cytotoxic substances that might cause apoptosis in cancer cells. Chemical compounds able to restore the level of PA catabolism in tumors could become potential antineoplastic agents. The search for activators of PA catabolism among bicyclononan-9-ones is a promising strategy for drug development. The aim of the study was to evaluate the biological activity of new 3,7-diazabicyclo[3.3.1]nonan-9-one derivatives that have antiproliferative properties by accelerating PA catabolism. Eight bispidine derivatives were synthetized and demonstrated the ability to activate PA catabolism in regenerating rat liver homogenates. However, only three of them demonstrated a potent ability to decrease the viability of cancer cells in the MTT assay. Compounds 4c and 4e could induce apoptosis more effectively in cancer HepG2 cells rather than in normal WI-38 fibroblasts. The lead compound 4e could significantly enhance cancer cell death, but not the death of normal cells if PAs were added to the cell culture media. Thus, the bispidine derivative 4e 3-(3-methoxypropyl)-7-[3-(1H-piperazin-1-yl)ethyl]-3,7-diazabicyclo[3.3.1]nonane could become a potential anticancer drug substance whose mechanism relies on the induction of PA catabolism in cancer cells. Full article

Antagonists of growth hormone-releasing hormone (GHRH) inhibit the growth of various tumors, including endometrial carcinomas (EC). However, tumoral receptors that mediate the antiproliferative effects of GHRH antagonists in human ECs have not been fully characterized. In this study, we investigated the expression of mRNA for GHRH and splice variants (SVs) of GHRH receptors (GHRH-R) in 39 human ECs and in 7 normal endometrial tissue samples using RT-PCR. Primers designed for the PCR amplification of mRNA for the full length GHRH-R and SVs were utilized. The PCR products were sequenced, and their specificity was confirmed. Nine ECs cancers (23%) expressed mRNA for SV1, three (7.7%) showed SV2 and eight (20.5%) revealed mRNA for SV4. The presence of SVs for GHRH-Rs could not be detected in any of the normal endometrial tissue specimens. The presence of specific, high affinity GHRH-Rs was also demonstrated in EC specimens using radioligand binding studies. Twenty-four of the investigated thirty-nine tumor samples (61.5%) and three of the seven corresponding normal endometrial tissues (42.9%) expressed mRNA for GHRH ligand. Our findings suggest the possible existence of an autocrine loop in EC based on GHRH and its tumoral SV receptors. The antiproliferative effects of GHRH antagonists on EC are likely to be exerted in part by the local SVs and GHRH system. Full article