Rho GTPase activating protein 21-mediated regulation of prostate cancer associated 3 gene in prostate cancer cell.

The overexpression of the prostate cancer antigen 3 (PCA3) gene is well-defined as a marker for prostate cancer (PCa) diagnosis. Although widely used in clinical research, PCA3 molecular mechanisms remain unknown. Herein we used phage display technology to identify putative molecules that bind to the promoter region of PCA3 gene and regulate its expression. The most frequent peptide PCA3p1 (80%) was similar to the Rho GTPase activating protein 21 (ARHGAP21) and its binding affinity was confirmed using Phage Bead ELISA. We showed that ARHGAP21 silencing in LNCaP prostate cancer cells decreased PCA3 and androgen receptor (AR) transcriptional levels and increased prune homolog 2 (PRUNE2) coding gene expression, indicating effective involvement of ARHGAP21 in androgen-dependent tumor pathway. Chromatin immunoprecipitation assay confirmed the interaction between PCA3 promoter region and ARHGAP21. This is the first study that described the role of ARHGAP21 in regulating the PCA3 gene under the androgenic pathway, standing out as a new mechanism of gene regulatory control during prostatic oncogenesis.

Rho GTPase activating protein 21-mediated regulation of prostate cancer associated 3 gene in prostate cancer cell

The overexpression of the prostate cancer antigen 3 (PCA3) gene is well-defined as a marker for prostate cancer (PCa) diagnosis. Although widely used in clinical research, PCA3 molecular mechanisms remain unknown. Herein we used phage display technology to identify putative molecules that bind to the promoter region of PCA3 gene and regulate its expression. The most frequent peptide PCA3p1 (80%) was similar to the Rho GTPase activating protein 21 (ARHGAP21) and its binding affinity was confirmed using Phage Bead ELISA. We showed that ARHGAP21 silencing in LNCaP prostate cancer cells decreased PCA3 and androgen receptor (AR) transcriptional levels and increased prune homolog 2 (PRUNE2) coding gene expression, indicating effective involvement of ARHGAP21 in androgen-dependent tumor pathway. Chromatin immunoprecipitation assay confirmed the interaction between PCA3 promoter region and ARHGAP21. This is the first study that described the role of ARHGAP21 in regulating the PCA3 gene under the androgenic pathway, standing out as a new mechanism of gene regulatory control during prostatic oncogenesis.

Effect of resistance training combined with ß-glucan ingestion on bone of ovariectomized mice.

OBJECTIVE: This study aimed to evaluate the effects of resistance training (RT) combined with prebiotic ß-glucan (BG) ingestion (Saccharomyces cerevisiae) in ovariectomized (OVX) mice. METHODS: Forty-eight mice were divided into six treatments: SHAM group and five OVX groups treated with saline (SAL), alendronate (ALE) (0.1 mg/kg), BG (62.5 mg/kg), RT (climbing a ladder with load) and the combination of BG + RT. All treatments were performed three times per week for 8 weeks starting 38 days after ovariectomy. RESULTS: OVX effectiveness was confirmed by a reduction in uterus mass (p < 0.05). Femur weight was higher in the SHAM group, followed by the ALE and RT groups with intermediate values and the BG + RT, BG and SAL groups with the lowest values (p < 0.05). The bone mineral density (BMDDEXA) results were higher for the SHAM and RT groups compared to the other groups (p < 0.05). RT provided similar bone mass and resistance to fracture to ALE and SHAM. We found a similar number of osteocytes in the RT and SHAM groups, which was significantly higher than that found in animals receiving BG (p < 0.05). The BG + RT combination increased calcium bone concentration. CONCLUSION: RT promoted benefits on bone health in the OVX model, which were not complemented by the consumption of BG.

Antimicrobial and cytotoxic activity of red propolis: an alert for its safe use.

AIMS: Red propolis is a resinous product popularly consumed in Brazil as it improves health, and it is considered a nutraceutical. The objective of this study was to test the antimicrobial activity of eight samples of red propolis from Brazil and Cuba to assess the possibility of application of this natural product as an antimicrobial agent, along with a study of its cytotoxic activity against non-tumor cell lines to evaluate at which concentrations it could be safely used. METHODS AND RESULTS: The chemical profile of the samples was evaluated by UHPLC-MS. All the samples presented antimicrobial activity which was tested using agar diffusion and serial dilution methods; and these samples displayed a better activity against most Gram-negative bacteria with minimum inhibitory concentration (MIC) in the range between 6·25 µg ml(-1) and 500 µg ml(-1). However our studies also revealed an inherent cytotoxic effect against HaCaT human keratinocytes and BALBc 3T3. CONCLUSIONS: To have a noncytotoxic and safe use of red propolis, it is necessary to use a concentration below the IC50 cytotoxic values. SIGNIFICANCE AND IMPACT OF THE STUDY: The traditional use of propolis does not necessarily guarantee its safety. The evaluation of the safety of bioactive natural products should always be considered together with the evaluation of the activity.

The queen is dead--long live the workers: intraspecific parasitism by workers in the stingless bee Melipona scutellaris.

Insect societies are well known for their high degree of cooperation, but their colonies can potentially be exploited by reproductive workers who lay unfertilized, male eggs, rather than work for the good of the colony. Recently, it has also been discovered that workers in bumblebees and Asian honeybees can succeed in entering and parasitizing unrelated colonies to produce their own male offspring. The aim of this study was to investigate whether such intraspecific worker parasitism might also occur in stingless bees, another group of highly social bees. Based on a large-scale genetic study of the species Melipona scutellaris, and the genotyping of nearly 600 males from 45 colonies, we show that approximately 20% of all males are workers' sons, but that around 80% of these had genotypes that were incompatible with them being the sons of workers of the resident queen. By tracking colonies over multiple generations, we show that these males were not produced by drifted workers, but rather by workers that were the offspring of a previous, superseded queen. This means that uniquely, workers reproductively parasitize the next-generation workforce. Our results are surprising given that most colonies were sampled many months after the previous queen had died and that workers normally only have a life expectancy of approximately 30 days. It also implies that reproductive workers greatly outlive all other workers. We explain our results in the context of kin selection theory, and the fact that it pays workers more from exploiting the colony if costs are carried by less related individuals.

Production of workers, queens and males in Plebeia remota colonies (Hymenoptera, Apidae, Meliponini), a stingless bee with reproductive diapause.

Queen, male and worker production was studied during one year in three Plebeia remota colonies from Atlantic Rainforest in Cunha, São Paulo State, and two from a subtropical Araucaria forest in Prudentópolis, Paraná State. All the colonies were kept in São Paulo city during our study. Plebeia remota has reproductive diapause during autumn and winter, which makes its biology of special interest. Brood production begins before spring, renewing the colony cycle. We sampled brood combs monthly in these five colonies. The number of cells in each comb varied significantly with time of the year; the smallest brood combs appear to be a consequence of reduced food availability. However, worker, queen and male frequencies did not differ significantly in time, and this presumably is due to the fact that they all are necessary for the growth, maintenance and reproduction of the colony. Although some molecular, morphological and behavioral differences have been detected in several studies comparing populations from Cunha and from Prudentópolis, we did not find significant differences between the colonies from these two localities in number of brood cells and worker, queen and male production.

Moscas-das-frutas (diptera: tephritidae) e seus parasitóides em plantas hospedeiras de três municípios do norte do estado de minas gerais

ABSTRACT This fruit-fly species survey was based on fruits sampled at several sites (urban and rural areas) in the counties of Jaíba, Janaíba and Nova Porteirinha, in Minas Gerais State, Brazil over a 50-month period (from May 1999 to April 2001 and from June 2002 to July 2004). Thirty-two fruit species in 17 families were sampled, but fruit flies emerged from only 18 host-fruit species. Ceratitis capitata(Wied.) and eight Anastrepha species A. fraterculus (Wiedemann), A. obliqua (Macquart), A. sororcula Zucchi, A. turpiniae Stone, A. zenildae Zucchi, A. pickeli Lima, A. montei Lima and Anastrepha n.sp.3 were collected. Medflies emerged mostly from introduced fruits and were predominant in the urban areas, while the Anastrepha species were predominant in the rural areas. Spondias tuberosa Arr. Câm. (umbu) and Psidium guajava L. (guava) were the hosts most infested by tephritid larvae. Seven fruit-fly parasitoid species were collected: Doryctobracon areolatus (Szépligeti) (more abundant), D. fluminensis (Lima), D. brasiliensis (Szépligeti), Opius bellus Gahan, Utetes anastrephae (Viereck), Diachasmimorpha longicaudata (Ashmead) and Aganaspis pelleranoi (Brèthes).

RESUMO O levantamento das moscas-das-frutas foi por meio de coleta de frutos em áreas rurais e urbanas de Jaíba, Janaúba e Nova Porteirinha, durante 50 meses (maio/1999 a abril/2001 e junho/2002 a julho/2004). Foram amostradas 32 espécies de frutos em 17 famílias, porém foram obtidas moscasdas-frutas em apenas 18 hospedeiros. Foram coletados exemplares de Ceratitis capitata (Wied.) e de oito espécies de Anastrepha: A. fraterculus (Wied.), A. obliqua (Macquart), A. sororcula Zucchi, A. turpiniae Stone, A. zenildae Zucchi, A. pickeli Lima, A. montei Lima e Anastrepha n.sp.3. C. capitata ocorreu principalmente em hospedeiros introduzidos e foi predominante em áreas urbanas. As espécies de Anastrepha predominaram em áreas rurais. Umbu (Spondias tuberosa Arr. Câm.) e goiaba (Psidium guajava L.) foram os hospedeiros mais infestados pelos tefritídeos. Sete espécies de parasitóides foram coletadas: Doryctobracon areolatus (Szépligeti)(mais numeroso), D. fluminensis (Lima), D. brasiliensis (Szépligeti), Opius bellus Gahan., Utetes anastrephae (Viereck), Diachasmimorpha longicaudata (Ashmead) e Aganaspis pelleranoi (Brèthes).