RESUMO
Ferritinophagy is a form of selective autophagy responsible for degrading intracellular ferritin, mediated by nuclear receptor coactivator 4 (NCOA4). NCOA4 plays significant roles in systemic iron homeostasis, and its disruption leads to simultaneous anemia and susceptibility to iron overload. The importance of iron colorectal cancer pathogenesis is well studied; however, the role of ferritinophagy in colon cancer cell growth has not been assessed. Disruption of ferritinophagy via NCOA4 knockout leads to only marginal differences in growth under basal and iron-restricted conditions. Moreover, NCOA4 played no significant role in cell death induced by 5-fluorouracil and erastin. Western blotting analysis for ferritin and transferrin receptor 1 found a dose-dependent effect on expression in both proteins in wild-type and NCOA4 knockout cell lines, but further investigation revealed no difference in growth response when treated at both high and low doses. Our data demonstrate a marginal role for ferritinophagy in growth both under normal and cytotoxic conditions in colon cancer cells, as well as a possible compensatory mechanism in colon cancer cells in response to ferroptosis induction.
Assuntos
Neoplasias do Colo/metabolismo , Ferritinas/metabolismo , Coativadores de Receptor Nuclear/metabolismo , Autofagia/efeitos dos fármacos , Autofagia/fisiologia , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/fisiologia , Neoplasias do Colo/fisiopatologia , Ferritinas/fisiologia , Homeostase/efeitos dos fármacos , Humanos , Ferro/metabolismo , Distúrbios do Metabolismo do Ferro , Coativadores de Receptor Nuclear/genética , Espécies Reativas de Oxigênio/metabolismoRESUMO
This report presents the results of two treatment cross-over investigations on 20 healthy male volunteers to assess the bioequivalence of two suppository products of diclofenac sodium. The study was carried out under US Food and Drug Administration Guidelines. The two products were voltaren (100 mg) suppository (Ciba-Giegy), as a reference product, and Inflaban (100 mg) suppository (The Arab Pharmaceutical Manufacturing Company, Ltd. "APM"), as a test product. Both products were administered rectally as a single dose (100 mg) separated by a one-week wash-out period. Following drug administration, blood samples were collected over 12 hr, and serum harvested from the blood was analyzed for diclofenac sodium using a sensitive and specific high performance liquid chromatographic assay. The results of this investigation indicated that there were no statistically significant differences between the two products in either the mean concentration-time profiles or in the obtained pharmacokinetic parameters, including area under the serum concentration-time curve for 12 hr (AUC(0-12h)), lag time between product administration and first appearance of the drug in serum (T(lag)), peak serum concentration (C(max)), and time to reach this peak serum concentration (T(max)). Concerning the relative extent of absorption, assessed by the AUC ratio (Inflaban/Voltaren) for 12 hr, the average value was found to be 1.00+/-0.09 with a 95% confidence limits (C.L.) of 0.82-1.18. Thus, these findings clearly indicate that the two products are bioequivalent in terms of rate and extent of drug absorption.
Assuntos
Anti-Inflamatórios não Esteroides/farmacocinética , Diclofenaco/farmacocinética , Administração Retal , Adulto , Anti-Inflamatórios não Esteroides/sangue , Área Sob a Curva , Disponibilidade Biológica , Estudos Cross-Over , Diclofenaco/sangue , Meia-Vida , Humanos , Masculino , Supositórios , Equivalência TerapêuticaRESUMO
OBJECTIVE: To determine if there are significant differences in biochemical characteristics, biopsy variables, histopathological data, and rates of prostate-specific antigen (PSA) recurrence between African-American (AA) and white American (WA) men undergoing radical prostatectomy (RP), as AA men are twice as likely to die from prostate cancer than their white counterparts. PATIENTS AND METHODS: We established a cohort of 1058 patients (402 AA, 646 WA) who had RP and were followed for PSA recurrence. Age, race, serum PSA, biopsy Gleason score, clinical stage, pathological stage, and PSA recurrence data were available for the cohort. The chi-square test of proportions and t-tests were used to assess basic associations with race, and log-rank tests and Cox regression models for time to PSA recurrence. Forward stepwise variable selection was used to assess the effect on the risk of PSA recurrence for race, adjusted by the other variables added one at a time. RESULTS: The AA men had higher baseline PSA levels, more high-grade prostatic intraepithelial neoplasia (HGPIN) in the biopsy, and more HGPIN in the pathology specimen than WA men. The AA men also had a shorter mean (sd) PSA doubling time before RP, at 4.2 (4.7) vs 5.2 (5.9) years. However, race was not an independent predictor of PSA recurrence (P = 0.225). Important predictors for PSA recurrence in a multivariable model were biopsy HGPIN (P < 0.014), unilateral vs bilateral cancer (P < 0.006), pathology Gleason score and positive margin status (both P < 0.001). CONCLUSIONS: This study indicates that while there are racial differences in baseline serum PSA and incidence of HGPIN, race is not an independent risk factor for PSA recurrence. Rather, other variables such as pathology Gleason score, bilateral cancers, HGPIN and margin positivity are independently associated with PSA recurrence. The PSA doubling time after recurrence may also be important, leading to the increased mortality of AA men with prostate cancer.