Decreased risk of renal cell carcinoma in patients with type 2 diabetes treated with sodium glucose cotransporter-2 inhibitors.

Patients with type 2 diabetes (T2D) are at a higher risk of developing renal cell carcinoma (RCC) than the general population. In vitro and in vivo investigations of the effects of sodium glucose cotransporter-2 inhibitors (SGLT2I) have shown a significantly reduced risk of RCC. However, the impact of these drugs on the incidence of RCC in the human population is unclear. This study aimed to examine the association between SGLT2I use and RCC risk in patients with T2D. We undertook a nationwide retrospective cohort study using the Health and Welfare Data Science Center database (2016-2020). The primary outcome was the risk of incident RCC by estimating hazard ratios (HRs) and 95% confidence intervals (CIs). Multiple Cox regression modeling was applied to analyze the association between SGLT2I use and RCC risk in patients with T2D. In a cohort of 241,772 patients with T2D who were using SGLT2Is and 483,544 participants who were not, 220 and 609 RCC cases, respectively, were recorded. The mean follow-up period of the study subjects was 2 years. There was a decreased risk of RCC for SGLT2I users after adjusting for the index year, sex, age, comorbidities, and concurrent medication (adjusted HR 0.68; 95% CI, 0.58-0.81). The sensitivity test for the propensity score 1:1-matched analyses showed similar results (adjusted HR 0.67; 95% CI, 0.55-0.81). The subgroup analysis revealed consistent results for sex, age (<70 years), and comorbidity with chronic kidney disease. The present study indicates that SGLT2I therapy significantly decreases RCC risk in patients with T2D. This finding was also consistent among the sensitivity test and subgroup analysis for those with or without chronic kidney disease/hypertension.

Modified three-layer vesicourethral reconstruction in robot-assisted radical prostatectomy can change cystography pattern and improve early recovery of continence.

BACKGROUND AND OBJECTIVES: To determine early continence outcomes after three-layer vesicourethral reconstruction during robot-assisted radical prostatectomy (RARP) and the role of postoperative cystography pattern. METHODS: Between May 2015 and January 2019, a total of 170 consecutive patients with localized prostate cancer who underwent RARP, were divided into one- and three-layer groups based on the method of vesicourethral reconstruction. Continent status, preoperative, intraoperative, postoperative, clinicopathological variables, and cystography parameters were analyzed. The patients were followed up for at least 12 months. RESULTS: Of the 170 consecutive patients, 85 with one-layer vesicourethral anastomosis, and 85 with three-layer reconstruction. The continence rates immediately after catheter removal, 4, 12, and 24 weeks after RARP were 47.1%, 75.3%, 92.9%, and 98.8% in the three-layer group; compared to 15.3%, 60%, 78.8%, and 90.6% in the one-layer group, respectively. In the multivariate analysis, three-layer reconstruction was the only independent variable with a 42% risk reduction of postprostatectomy incontinence (hazard ratio (HR): 0.58, 95% confidence interval (CI) = 0.42-0.80, p = 0.001). Cystography in the three-layer group revealed less anastomotic leakage, less sharp bladder neck angle, and higher bladder neck level category. CONCLUSIONS: Three-layer anatomical reconstruction demonstrated promising early continence outcomes, and postoperative cystography revealed a specific pattern more associated with continence.

ProDisc-C versus anterior cervical discectomy and fusion for the surgical treatment of symptomatic cervical disc disease: two-year outcomes of Asian prospective randomized controlled multicentre study.

PURPOSE: Our study aimed to evaluate non-inferiority of ProDisc-C to anterior cervical discectomy and fusion (ACDF) in terms of clinical outcomes and incidence of adjacent segment disease (ASD) at 24-months post-surgery in Asian patients with symptomatic cervical disc disease (SCDD). METHODS: This multicentre, prospective, randomized controlled trial was initiated after ethics committee approval at nine centres (China/Hong Kong/Korea/Singapore/Taiwan). Patients with single-level SCDD involving C3-C7-vertebral segments were randomized (2:1) into: group-A treated with ProDisc-C and group-B with ACDF. Assessments were conducted at baseline, 6-weeks, 3/6/12/18/24-months post-surgery and annually thereafter till 84-months. Primary endpoint was overall success at 24-months, defined as composite of: (1) ≥ 20% improvement in neck disability index (NDI); (2) maintained/improved neurologic parameters; (3) no implant removal/revision/re-operation at index level; and (4) no adverse/severe/life-threatening events. RESULTS: Of 120 patients (80ProDisc-C,40ACDF), 76 and 37 were treated as per protocol (PP). Overall success (PP) was 76.5% in group-A and 81.8% in group-B at 24-months (p = 0.12), indicating no clear non-inferiority of ProDisc-C to ACDF. Secondary outcomes improved for both groups with no significant inter-group differences. Occurrence of ASD was higher in group-B with no significant between-group differences. Range of motion (ROM) was sustained with ProDisc-C but lost with ACDF at 24-months. CONCLUSION: Cervical TDR with ProDisc-C is feasible, safe, and effective for treatment of SCDD in Asians. No clear non-inferiority was demonstrated between ProDisc-C and ACDF. However, patients treated with ProDisc-C demonstrated significant improvement in NDI, neurologic success, pain scores, and 36-item-short-form survey, along with ROM preservation at 24-months. Enrolment difficulties resulted in inability to achieve pre-planned sample size to prove non-inferiority. Future Asian-focused, large-scale studies are needed to establish unbiased efficacy of ProDisc-C to ACDF.

Peri-radiosurgical administration of bevacizumab improves radiographic response to single and fractionated stereotactic radiosurgery for large brain metastasis.

INTRODUCTION: Stereotactic radiosurgery (SRS) is a standard of care for brain metastases (BM) patients, yet large BM are at a greater risk for radionecrosis and local progression (LP). Concomitant bevacizumab and radiotherapy has been shown to improve outcomes in primary and metastatic brain tumors. This retrospective study investigated the efficacy and safety of concurrent bevacizumab and SRS for large BM. METHODS: From 2015 to 2019, patients with a BM diameter ≥ 2 cm who received either combination therapy (n = 49, SRS + BVZ group), or SRS alone (n = 73, SRS group) were enrolled. Bevacizumab was given peri-radiosurgically with a 2-week interval. Radiographic response was assessed using the RECIST version 1.1. Competing risk and logistic regression analysis were performed to evaluate prognostic factors. RESULTS: Radiographic response was achieved in 41 patients (84%) in the SRS + BVZ group and 37 patients (51%) in the SRS group (p = 0.001). In the multivariate regression analysis, concurrent bevacizumab was independently associated with a better radiographic response (p = 0.003). The cumulative incidences of LP and ≥ grade 2 radionecrosis at 12 months between the SRS + BVZ group and SRS group were 2% versus 6.8%, and 14.3% versus 14.6%, respectively. For patients with BM size ≥ 3 cm, the cumulative incidence of LP was significantly lower in the SRS + BVZ group (p = 0.03). No ≥ grade 4 toxicity was observed in either group. CONCLUSIONS: Concurrent bevacizumab and SRS for large BM is highly effective, with a better radiographic response and minimal excessive treatment-related toxicities. Peri-radiosurgical bevacizumab preferentially reduced the risk of LP, especially for BM size ≥ 3 cm.

Oral treatment for diabetes using α-glucosidase inhibitors was a risk factor for chronic obstructive pulmonary disease: a cohort study.

Objectives: Currently, diabetes mellitus (DM) and chronic obstructive pulmonary disease (COPD) have proven to be risk factors for each other. This study aimed to determine the risk relationship between COPD and five common oral medications for DM among patients with DM. Methods: This population-based cohort study was conducted from 2008 to 2013. Patient data were retrieved from the Longitudinal Health Insurance Database (LHID) of the National Health Insurance Research Database (NHIRD). After pairing by gender, age, and index date, time-to-event analysis and multiple regression analysis were performed to determine the factors associated with COPD in patients taking oral medication for DM, including age, gender, income, and comorbidities. We identified 1,028 patients who took oral medication for DM and 1,028 controls who did not take oral medication for DM. Results: We observed that the use of α-glucosidase inhibitors was associated with a higher risk of COPD (hazard ratio [HR]: 1.964, 95% confidence interval [CI]: 1.207-2.380). Furthermore, compared with the control group, α-glucosidase inhibitor users had a higher risk of COPD (HR: 2.295, 95% CI: 1.304-4.038), and no significant difference was observed in other oral medications for DM. Conclusions: Based on present results, we could suggest that patients with DM who used α-glucosidase inhibitors are probably a higher risk of COPD. We recommend that in the future, treatment with α-glucosidase inhibitors upregulate the occurrence of COPD might through gastrointestinal side effects and malnutrition.

Genistein enhances the effects of L-asparaginase on inducing cell apoptosis in human leukemia cancer HL-60 cells.

Genistein (GEN) has been shown to induce apoptotic cell death in various human cancer cells. L-asparaginase (Asp), a clinical drug for leukemia, has been shown to induce cell apoptosis in leukemia cells. No available information concerning GEN combined with Asp increased the cell apoptosis compared to GEN or Asp treatment alone. The objective of this study is to evaluate the anti-leukemia activity of GEN combined with Asp on human leukemia HL-60 cells in vitro. The cell viability, the distribution of cell cycle, apoptotic cell death, and the level of ΔΨm were examined by flow cytometric assay. The expressions of apoptosis-associated proteins were measured by western blotting. GEN combined with Asp revealed a more significant decrease in total viable cells and induced a higher percentage of G2/M phase arrest, DNA damage, and cell apoptosis than that of GEN or Asp treatment only in HL-60 cells. Furthermore, the combined treatments (GEN and Asp) showed a higher decrease in the level of ΔΨm than that of GEN or Asp treatment only. These results indicated that GEN combined with Asp induced mitochondria dysfunction by disrupting the mitochondrial membrane potential. The results from western blotting demonstrated that the treatment of GEN combined with Asp showed a higher increase in the levels of Bax and Bak (pro-apoptotic proteins) and an active form of caspase-3 and a higher decrease in Bcl-2 (anti-apoptotic protein) than that of GEN or Asp treatment alone. GEN significantly enhances the efficiency of Asp on cytotoxic effects (the induction of apoptosis) in HL-60 cells.

Effects of Focal Radiation on [18 F]-Fluoro-D-Glucose Positron Emission Tomography in the Brains of Miniature Pigs: Preliminary Findings on Local Metabolism.

OBJECTIVES: It would be a medically important advance if durable and focal neuromodulation of the brain could be delivered noninvasively and without ablation. This ongoing study seeks to elucidate the effects of precisely delivered ionizing radiation upon focal brain metabolism and the corresponding cellular integrity at that target. We hypothesize that focally delivered ionizing radiation to the brain can yield focal metabolic changes without lesioning the brain in the process. MATERIALS AND METHODS: We used stereotactic radiosurgery to deliver doses from 10 Gy to 120 Gy to the left primary motor cortex (M1) of Lee Sung miniature pigs (n = 8). One additional animal served as a nonirradiated control. We used positron emission tomography-computed tomography (PET-CT) to quantify radiation dose-dependent effects by calculating the ratio of standard uptake values (SUV) of 2-deoxy-2-[18 F]-fluoro-D-glucose (18 F-FDG) between the radiated (left) and irradiated (right) hemispheres across nine months. RESULTS: We found that the FDG-PET SUV ratio at the targeted M1 was significantly lowered from the pre-radiation baseline measurements for animals receiving 60 Gy or higher, with the effect persisting at nine months after radiosurgery. Only at 120 Gy was a lesion suggesting ablation visible at the M1 target. Animals treated at 60-100 Gy showed a reduced signal in the absence of an identifiable lesion, a result consistent with the occurrence of neuromodulation. CONCLUSION: Focal, noninvasive, and durable changes in brain activity can be induced without a magnetic resonance imaging (MRI)-visible lesion, a result that may be consistent with the occurrence of neuromodulation. This approach may provide new venues for the investigation of neuromodulatory treatments for disorders involving dysfunctional brain circuits. Postmortem pathological analysis is needed to elucidate whether there have been morphological changes not detected by MRI.

The association between SGLT2 inhibitors and new-onset arrhythmias: a nationwide population-based longitudinal cohort study.

BACKGROUND: Clinical trials have shown the cardiovascular protective effect of sodium-glucose cotransporter-2 (SGLT2) inhibitors and reduced hospitalization for heart failure. However, no study has investigated the association between SGLT2 inhibitors and the risk of arrhythmias. This study aimed to evaluate the risk of new-onset arrhythmias (NOA) and all-cause mortality with the use of SGLT2 inhibitors. METHODS: This was a population-based cohort study utilizing Taiwan's National Health Insurance Research Database. Each patient aged 20 years and older who took SGLT2 inhibitors was assigned to the SGLT2 inhibitor group, whereas sex-, age-, diabetes mellitus duration-, drug index date-, and propensity score-matched randomly selected patients without SGLT2 inhibitors were assigned to the non-SGLT2 inhibitor group. The study outcome was all-cause mortality and NOA. RESULTS: A total of 399,810 patients newly diagnosed with type 2 DM were enrolled. A 1:1 matching propensity method was used to match 79,150 patients to 79,150 controls in the non-SGLT2 inhibitors group for analysis. The SGLT2 inhibitor group was associated with a lower risk of all-cause mortality [adjusted hazard ratio (aHR) 0.547; 95% confidence interval (CI) 0.482-0.621; P = 0.0001] and NOA (aHR 0.830; 95% CI 0.751-0.916; P = 0.0002). CONCLUSIONS: Patients with type 2 DM prescribed with SGLT2 inhibitors were associated with a lower risk of all-cause mortality and NOA compared with those not taking SGLT2 inhibitors in real-world practice.

Association between statin use and osteoporotic fracture in patients with chronic obstructive pulmonary disease: a population-based, matched case-control study.

BACKGROUND: In the recent years, chronic obstructive pulmonary disease (COPD) has been found to be associated with a higher risk of new-onset osteoporotic fracture (NOF). However, the existence of such an association in the COPD patients receiving statin treatment remains unknown. The present study aimed to investigate the association between COPD and NOF in statin-treated patients. METHODS: The present study was conducted over a period of 10 years (January 2004 to December 2013) in Taiwan. COPD patients receiving statin treatment were included in the statin user group, whereas the randomly selected statin non-users, with 1:1 matching for sex, age, index date, and Charlson Comorbidity Index, were included in the statin non-user group. The hazard ratio (HR) of NOFs in COPD patients was estimated between statin user and non-user groups. RESULTS: A total of 86,188 cases were identified as the statin-treated patients, and 86,188 subjects were included in the control group of statin non-users. Initially, the risk of NOF was found to be higher among the statin users as compared to non-users [HR, 1.12; 95% confidence interval (CI), 1.01-1.25]. However, the calculation of risk for NOFs after the adjustment for age, sex, comorbidities, and concurrent medications indicated no association of NOF (HR, 0.81; 95% CI, 0.55-1.21) with COPD in patients receiving statin treatment as compared to statin non-users. CONCLUSION: The results of the study provided first evidence for the absence of any association between COPD and NOFs in statin-treated patients during a follow-up period of 10 years. Thus, the findings of this study might support the hypothesis stating the potent pleiotropic effects of statins. In clinical practice, these drugs might prove beneficial for the patients with COPD.

Evaluation of cytotoxicity, apoptosis, and genotoxicity induced by indium chloride in macrophages through mitochondrial dysfunction and reactive oxygen species generation.

Due to rapid advances in the era of electronic technologies, indium has played the important material for the production of liquid crystal display screens in the semiconductor and optoelectronic industries. The present study focuses on evaluating the toxic effects and related mechanisms of indium chloride (InCl3) on RAW264.7 macrophages. Cytotoxicity was induced by InCl3 in a concentration- and time-dependent manner. InCl3 had the ability to induce macrophage death through apoptosis rather than through necrosis. According to the cytokinesis-block micronucleus assay and alkaline single-cell gel electrophoresis assay, InCl3 induced DNA damage, also called genotoxicity, in a concentration-dependent manner. Cysteine-dependent aspartate-directed protease (caspase)-3, -8, and -9 were activated by InCl3 in a concentration-dependent manner. Mitochondria dysfunction and cytochrome c release from the mitochondria were induced by InCl3 in a concentration-dependent manner. Downregulation of BCL2 and upregulation of BAD were induced by InCl3 in a concentration-dependent manner. More, we proposed that InCl3 treatment generated reactive oxygen species (ROS) in a concentration-dependent manner. In conclusion, the current study revealed that InCl3 induced macrophage cytotoxicity, apoptosis, and genotoxicity via a mitochondria-dependent apoptotic pathway and ROS generation.

Gastric Calcifying Fibrous Tumor: An Easy Misdiagnosis as Gastrointestinal Stromal Tumor-A Systemic Review.

Background and Objectives: Calcifying fibrous tumor (CFT) in the stomach is extremely rare and is easily misdiagnosed as a gastrointestinal stromal tumor (GIST). This study aims to determine the best method to differentiate between gastric CFT and GIST after a systemic review and meta-analysis. Materials and Methods: A systematic search of articles using electronic databases (MEDLINE, EMBASE, and LILACS) was conducted and resulted in 162 articles with 272 CFT cases published from January 1988 to September 2019. Results: Of these cases, 272 patients, 60 patients with gastric CFT (32 men and 28 women, mean age 49.2 years) were analyzed. The mean tumor size was 2.4 cm in patients with gastric CFT. Both endoscopic ultrasound (EUS) and computed tomography (CT) findings revealed well-defined (100% vs. 77.8%), heterogeneous (100% vs. 77.8%), iso-hypoechoic (71.4% vs. 33.3%), and calcified (85.7% vs. 77.8%) lesions, respectively. The majority of patients (53.3%) were symptomatic, with the most common symptom being abdominal discomfort (55.6%). None of the patients with gastric CFT showed recurrence after treatment, and most patients received nonendoscopic treatment (56%, n = 28/50). Both age and tumor size were statistically significant in patients with gastric CFT than GIST (49.2 vs. 65.0 years and 2.4 vs. 6.0 cm; both p < 0.001). The ratio of children among patients with CFT (5%) and GIST (0.05%) was also significantly different (p = 0.037). The calcification rates of gastric CFT had significantly higher calcification rates than GIST on images of EUS and CT (85.7% vs. 3.6% and 77.8% vs. 3.6%; both p < 0.001). Conclusions: Compared with patients with GIST, patients with gastric CFT were younger, had smaller tumor size, and were symptomatic. Furthermore, gastric CFT was well-defined, heterogeneous in the third layer, and had high calcification rates on the images.

Constituents and Anti-Multidrug Resistance Activity of Taiwanofungus camphoratus on Human Cervical Cancer Cells.

Resistance to anti-cancer drugs is one of the main factors of treatment failure resulting in high morbidity. Among the reasons of resistance, overexpression of efflux pumps leading to multidrug resistance is an important issue that needs to be solved. Taiwanofungus camphoratus has been used as a nutritional supplement to treat various cancers. However, its effects on the resistance to chemotherapeutic agents are still unknown. In this study, we report four new chemical constituents of T. camphoratus isolated from an ether extract: camphoratins K (1) and N (2) and benzocamphorins G (3) and I (4). Furthermore, we evaluated zhankuic acids A-C for their P-glycoprotein (P-gp) inhibitory effects. The results showed that zhankuic acid A was the most potent P-gp inhibitor compound and (at 20 µM) could reverse drug resistance in human cancer cells, restoring an IC50 of 78.5 nM for doxorubicin, of 48.5 nM for paclitaxel, and of 321.5 nM for vincristine, indicating a reversal fold of 48, 38, and 45 times, respectively. This study provides support for the use of T. camphoratus in the further development of cancer therapy.

Antihyperglycemic drugs use and new-onset atrial fibrillation in elderly patients.

BACKGROUND: Antihyperglycemic drugs have been linked to new-onset atrial fibrillation (NAF). However, the effect of the different classes of antihyperglycemic drugs on the development of NAF in elderly patients has not been well studied. In this study, we investigated the association between different classes of antihyperglycemic drugs and NAF in elderly patients. MATERIALS AND METHODS: This was a nested case-control study performed using the database of National Health Insurance programme in Taiwan. Each participant aged 65 years and older who were NAF from 2005 to 2012 were assigned to the NAF group, whereas case was sex-, age-, diabetes duration-, index date-matched, and Charlson Comorbidity Index score-matched randomly selected participant without NAF were assigned to the non-NAF group. Multivariable logistic regression model was used for the estimation of odds ratios (ORs) and 95% confidence intervals (CIs) of NAF associated with use of different classes of antihyperglycemic agents. Nonusers served as the reference group. RESULTS: We identified 1958 cases and 7832 controls. The risk of NAF after adjusting for sex, age, comorbidities and concurrent medication was higher among the users of insulin than among the nonusers (OR, 1·58; 95% CI, 1·37-1·82). Patients who took dipeptidyl peptidase 4 inhibitors were at lower risk of developing NAF than the nonusers (OR, 0·65; 95% CI, 0·45-0·93). CONCLUSIONS: In this population, use of dipeptidyl peptidase 4 inhibitor was associated with a low risk of NAF. Insulin use was associated with a significant increase in the risk of NAF during the long-term follow-up.

Saddle pulmonary emboli mimicking pulmonary artery dissection.

Pulmonary embolism (PE) can be a potentially fatal condition and requires early diagnosis. It is a frequently underdiagnosed, underestimated, and undertreated disease because of various features and nonspecific clinical presentation. Laboratory D-dimer test, lung scan, and echocardiography can help in making the diagnosis. Recently, computed tomography has been most common used for the diagnosis. We report a case of pulmonary embolism mimicking pulmonary artery dissection by initially using images from computed tomography. Further evaluation of the computed tomographic images using coronal plane confirmed the diagnosis of pulmonary embolism. Because the treatment modalities are completely different between the 2 diseases, we emphasize that 2 different orthogonal planes are necessary for diagnosis using computed tomographic image examination.

Structural basis for catalysis and ubiquitin recognition by the severe acute respiratory syndrome coronavirus papain-like protease.

Papain-like protease (PLpro) is one of two cysteine proteases involved in the proteolytic processing of the polyproteins of Severe acute respiratory syndrome coronavirus (SARS-CoV). PLpro also shows significant in vitro deubiquitinating and de-ISGylating activities, although the detailed mechanism is still unclear. Here, the crystal structure of SARS-CoV PLpro C112S mutant in complex with ubiquitin (Ub) is reported at 1.4 Šresolution. The Ub core makes mostly hydrophilic interactions with PLpro, while the Leu-Arg-Gly-Gly C-terminus of Ub is located in the catalytic cleft of PLpro, mimicking the P4-P1 residues and providing the first atomic insights into its catalysis. One of the O atoms of the C-terminal Gly residue of Ub is located in the oxyanion hole consisting of the main-chain amides of residues 112 and 113. Mutations of residues in the PLpro-Ub interface lead to reduced catalytic activity, confirming their importance for Ub binding and/or catalysis. The structure also revealed an N-cyclohexyl-2-aminethanesulfonic acid molecule near the catalytic triad, and kinetic studies suggest that this binding site is also used by other PLpro inhibitors. Overall, the structure provides a foundation for understanding the molecular basis of coronaviral PLpro catalysis.

Suppressing the formation of lipid raft-associated Rac1/PI3K/Akt signaling complexes by curcumin inhibits SDF-1α-induced invasion of human esophageal carcinoma cells.

Stromal cell-derived factor-1α (SDF-1α) is a ligand for C-X-C chemokine receptor type 4 (CXCR4), which contributes to the metastasis of cancer cells by promoting cell migration. Here, we show that the SDF-1α/CXCR4 axis can significantly increase invasion of esophageal carcinoma (EC) cells. We accomplished this by examining the effects of CXCR4 knockdown as well as treatment with a CXCR4-neutralizing antibody and the CXCR4-specific inhibitor AMD3100. Curcumin suppressed SDF-1α-induced cell invasion and matrix metalloproteinase-2 (MMP-2) promoter activity, cell surface localization of CXCR4 at lipid rafts, and lipid raft-associated ras-related C3 botulinum toxin substrate 1 (Rac1)/phosphatidylinositol 3-kinase (PI3K) p85α/Akt signaling. Curcumin inhibited SDF-1α-induced cell invasion by suppressing the Rac1-PI3K signaling complex at lipid rafts but did not abrogate lipid raft formation. We further demonstrate that the attenuation of lipid raft-associated Rac1 activity by curcumin was critical for the inhibition of SDF-1α-induced PI3K/Akt/NF-κB activation, cell surface localization of CXCR4 at lipid rafts, MMP-2 promoter activity, and cell invasion. Collectively, our results indicate that curcumin inhibits SDF-1α-induced EC cell invasion by suppressing the formation of the lipid raft-associated Rac1-PI3K-Akt signaling complex, the localization of CXCR4 with lipid rafts at the cell surface, and MMP-2 promoter activity, likely through the inhibition of Rac1 activity.

The roles of endoplasmic reticulum stress and mitochondrial apoptotic signaling pathway in quercetin-mediated cell death of human prostate cancer PC-3 cells.

Prostate cancer has its highest incidence and is becoming a major concern. Many studies have shown that traditional Chinese medicine exhibited antitumor responses. Quercetin, a natural polyphenolic compound, has been shown to induce apoptosis in many human cancer cell lines. Although numerous evidences show multiple possible signaling pathways of quercetin in apoptosis, there is no report to address the role of endoplasmic reticulum (ER) stress in quercetin-induced apoptosis in PC-3 cells. The purpose of this study was to investigate the effects of quercetin on the induction of the apoptotic pathway in human prostate cancer PC-3 cells. Cells were treated with quercetin for 24 and 48 h and at various doses (50-200 µM), and cell morphology and viability decreased significantly in dose-dependent manners. Flow cytometric assay indicated that quercetin at 150 µM caused G0/G1 phase arrest (31.4-49.7%) and sub-G1 phase cells (19.77%) for 36 h treatment and this effect is a time-dependent manner. Western blotting analysis indicated that quercetin induces the G0/G1 phase arrest via decreasing the levels of CDK2, cyclins E, and D proteins. Quercetin also stimulated the protein expression of ATF, GRP78, and GADD153 which is a hall marker of ER stress. Furthermore, PC-3 cells after incubation with quercetin for 48 h showed an apoptotic cell death and DNA damage which are confirmed by DAPI and Comet assays, leading to decrease the antiapoptotic Bcl-2 protein and level of ΔΨm , and increase the proapoptotic Bax protein and the activations of caspase-3, -8, and -9. Moreover, quercetin promoted the trafficking of AIF protein released from mitochondria to nuclei. These data suggest that quercetin may induce apoptosis by direct activation of caspase cascade through mitochondrial pathway and ER stress in PC-3 cells.