Resveratrol enhanced chemosensitivity by reversing macrophage polarization in breast cancer

BackgroundResveratrol, a naturally occurring polyphenolic compound, has been shown to inhibit cancer growth by targeting several cancer-related signalling pathways. In the tumor microenvironment (TME), tumor-associated macrophages (TAMs) are the most abundant leukocyte population that are associated with poor prognosis in over 80% of breast cancer cases. However, little is known about the effect of resveratrol in the TME.MethodsIn this study, MDA-MB-231(MB231), cisplatin resistance MDA-MB-231 (cisR), and T47D were used to examine the antitumor effect of resveratrol. The effectiveness of resveratrol, together with cisplatin as breast cancer treatment was investigated in vivo. Gene expressions of M1 (iNOS and CXCL10) and M2 (ARG1, CD163 and MRC1) markers in differentiated macrophages derived from THP-1 cells were examined to investigate the effect of resveratrol on TAM polarization in breast cancer progression.ResultsOur results demonstrated that resveratrol significantly reduced cell proliferation and enhanced chemosensitivity in breast cancer cells by inhibiting production of IL-6 and STAT3 activation. Treatment of resveratrol increased CXCL10 (M1 marker) expression. Further, resveratrol decreased IL-6 levels in LPS-treated differentiated macrophages. The use of resveratrol with cisplatin inhibited suppressed tumor growth when compared with cisplatin alone.ConclusionThis study revealed that resveratrol inhibited breast cancer cell proliferation by promoting M1/M2 macrophage polarization ratio and suppressing IL-6/pSTAT3 pathway.

Resveratrol enhanced chemosensitivity by reversing macrophage polarization in breast cancer.

BACKGROUND: Resveratrol, a naturally occurring polyphenolic compound, has been shown to inhibit cancer growth by targeting several cancer-related signalling pathways. In the tumor microenvironment (TME), tumor-associated macrophages (TAMs) are the most abundant leukocyte population that are associated with poor prognosis in over 80% of breast cancer cases. However, little is known about the effect of resveratrol in the TME. METHODS: In this study, MDA-MB-231(MB231), cisplatin resistance MDA-MB-231 (cisR), and T47D were used to examine the antitumor effect of resveratrol. The effectiveness of resveratrol, together with cisplatin as breast cancer treatment was investigated in vivo. Gene expressions of M1 (iNOS and CXCL10) and M2 (ARG1, CD163 and MRC1) markers in differentiated macrophages derived from THP-1 cells were examined to investigate the effect of resveratrol on TAM polarization in breast cancer progression. RESULTS: Our results demonstrated that resveratrol significantly reduced cell proliferation and enhanced chemosensitivity in breast cancer cells by inhibiting production of IL-6 and STAT3 activation. Treatment of resveratrol increased CXCL10 (M1 marker) expression. Further, resveratrol decreased IL-6 levels in LPS-treated differentiated macrophages. The use of resveratrol with cisplatin inhibited suppressed tumor growth when compared with cisplatin alone. CONCLUSION: This study revealed that resveratrol inhibited breast cancer cell proliferation by promoting M1/M2 macrophage polarization ratio and suppressing IL-6/pSTAT3 pathway.

Expanded criteria for pretreatment staging CT in breast cancer.

BACKGROUND: There is wide variation in the approach to staging for distant metastatic disease in breast cancer. This study sought to identify factors predictive of distant metastatic disease at presentation to enable appropriate selection of patients for pretreatment CT. METHODS: Data were collected retrospectively for all patients with newly diagnosed breast cancer (screening and symptomatic) over 3 years (2014-2017). Detailed demographic, pathological, biological, and management data were recorded at presentation, and outcome data were recorded after follow-up. Binomial logistic regression was used to identify variables independently associated with distant metastatic disease at presentation. RESULTS: A total of 1377 patients with newly diagnosed breast cancer were identified, of whom 1025 had complete data; 323 staging CT examinations were performed. Distant metastases were identified at presentation in 47 (4.6 per cent). Some 30 of 47 patients with metastatic disease met established criteria for staging (T4, recurrence, symptoms of possible distant metastases), leaving 17 patients with metastatic disease potentially missed by use of these criteria alone. Multivariable analysis showed that tumour size at least 3 cm combined with sonographically abnormal axillary lymph nodes predicted a high probability of distant metastatic disease at presentation (positive predictive value 18.8 per cent, odds ratio 4.83, P < 0.001). Addition of this criterion increased the positive CT rate to 17.1 per cent. CONCLUSION: Selective pretreatment CT staging can be further optimized with the addition of tumour size at least 3 cm with abnormal axillary nodes to established staging criteria.

Diagnostic utility of additional whole-chest CT as part of an acute abdominal pain CT imaging pathway during the COVID-19 pandemic.

AIM: To evaluate the diagnostic utility of additional whole-chest computed tomography (CT) in identifying otherwise unheralded COVID-19 lung disease as part of an acute abdominal pain CT imaging pathway in response to the COVID-19 pandemic. MATERIALS AND METHODS: Consecutive patients (n=172) who underwent additional whole-chest CT via a COVID-19 acute abdominal pain CT imaging pathway between 27 March and 3 May 2020 were evaluated in this retrospective single-centre study. Chest CT examinations were graded as non-COVID-19, indeterminate for, or classic/probable for COVID-19. CT examinations in the latter two categories were further divided into one of three anatomical distributions (lung base, limited chest [below carina], whole chest [above carina]) based on location of findings. Reverse transcriptase-polymerase chain reaction (RT-PCR) results and clinical features of COVID-19 were assessed to determine if COVID-19 was clinically suspected at the time of CT referral. RESULTS: Twenty-seven of the 172 (15.7%) patients had CT features potentially indicative of COVID-19 pneumonia, 6/27 (3.5%) demonstrating a classic/probable pattern and 21/27 (12.2%) demonstrating an indeterminate pattern. After correlation with clinical features and RT-PCR 8/172 (4.7%) were defined as COVID-19 positive, of which only 1/172 (0.6%) was clinically unsuspected of COVID-19 at the time of CT referral. All COVID-19 positive cases could be identified on review of the lung base alone. CONCLUSION: Whole-chest CT as part of an acute abdominal pain CT imaging pathway has a very low diagnostic yield for our cohort of patients. All COVID-19-positive patients in our cohort were identified on review of the lung bases on the abdominal CT and this offers an alternative imaging approach in this patient group.

Higher sea fish intake is associated with greater bone mass and lower osteoporosis risk in postmenopausal Chinese women.

SUMMARY: We examined the cross-sectional association of the intakes of different types of fishes with bone mass and osteoporosis risk in postmenopausal Chinese women. We found that higher intake of sea fish is independently associated with greater bone mass and lower osteoporosis risk among postmenopausal Chinese women. INTRODUCTION: Fish contains many important nutrients that are beneficial on bone health, but limited data on the relationship between fish intake and bone health are available. We examined the association of the intakes of different types of fishes with bone mineral density (BMD) and bone mineral content (BMC) and osteoporosis risk. METHODS: This population-based cross-sectional study was conducted among 685 postmenopausal Chinese women. Habitual dietary intakes were assessed using food frequency questionnaire. BMD and BMC at the whole body, lumbar spine, and left hip were measured with dual-energy x-ray absorptiometry. RESULTS: After adjusting for the potential confounders, we observed dose-dependent relations between sea fish intake and BMDs, BMCs, and osteoporosis risk; the mean BMDs were 3.2-6.8% higher, and BMCs 5.1-9.4% higher in the top quintile groups (Q5) of sea fish intake than in the bottom quintile (Q1) at the whole body and hip sites (p < 0.05); the odds ratios (95% confidence interval (CI)) for osteoporosis (T-score < -2.5) in Q5 were 0.23 (0.08-0.66), 0.12 (0.03-0.59), and 0.06 (0.01-0.44) compared with those in Q1 at the whole body, total hip, and femur neck, respectively. No independent association between consumption of freshwater fish or shellfish and bone mass was observed. CONCLUSION: Higher intake of sea fish is independently associated with greater bone mass and lower osteoporosis risk among postmenopausal Chinese women.

Validity of body mass index and waist circumference in the classification of obesity as compared to percent body fat in Chinese middle-aged women.

OBJECTIVE: To evaluate the validity of currently recommended obesity cutoffs of body mass index (BMI, in kg/m(2)) and waist circumference (WC, in cm) for Asians by the WHO/IASO/IOTF and for Chinese by the Working Group on Obesity in China (WGOC) using the percentage body fat (%BF)-obesity criteria. DESIGN: A cross-sectional study. SUBJECTS: A total of 1122 community-based Hong Kong Chinese women aged between 41 and 63 years. MEASUREMENTS: Total %BF and percent truncal fat (%TF) were measured using dual-energy X-ray absorptiometry. Anthropometric indices were measured using standard methods. RESULTS: Regression analyses showed that the BMI cutoffs of 23, 24, 25, and 28 kg/m(2) corresponded to the %BF of 34.8, 35.9, 36.9 and 39.5%, and the 80 cm WC corresponded to 34% TF, respectively. Compared with the %BF obesity cutoff (>/=40%), the WHO/IASO/IOTF BMI-obesity criterion (>/=25) shows a good sensitivity (75%) and specificity (71%); and the WGOC criterion (BMI>/=28) had a low sensitivity (41%) but an excellent specificity (93%), respectively. Corresponding to the BMI cutoffs of 23, 24, 25 and 28 kg/m(2), the %BF cutoffs associated with peak kappa statistic were 33, 34, 35 and 40%, and the relevant %TF linked with 80 cm WC was 33%, respectively. CONCLUSION: BMI and WC have a good accuracy in the prediction of obesity. Our findings suggest that the WGOC BMI cutoffs are appropriate, but 80 cm of WC is a very rigorous cutoff for this population when using the criteria of 34 and 40% of body fat or truncal fat for overweight and obesity.

Test-retest reliability and factor structures of organizational citizenship behavior for Hong Kong workers.

In 1990 Podsakoff, MacKenzie, Moorman, and Fetter developed a scale to measure the five dimensions of organizational citizenship behavior. Test-retest data over 15 weeks are reported for this scale for a sample of 82 female and 32 male Chinese tellers (ages 18 to 54 years) from a large international bank in Hong Kong. Stability was .83, and there was no significant change between Times 1 and 2. Analysis indicated the five-factor structure and showed it to be a reliable measure when used with a nonwestern sample.

The L3 loop and C-terminal phosphorylation jointly define Smad protein trimerization.

Smad proteins mediate the transforming growth factor beta responses. C-terminal phosphorylation of R-Smads leads to the recruitment of Smad4 and the formation of active signaling complexes. We investigated the mechanism of phosphorylation-induced Smad complex formation with an activating pseudo-phosphorylated Smad3. Pseudo-phosphorylated Smad3 has a greater propensity to homotrimerize, and recruits Smad4 to form a heterotrimer containing two Smad3 and one Smad4. The trimeric interaction is mediated through conserved interfaces to which tumorigenic mutations map. Furthermore, a conserved Arg residue within the L3 loop, located near the C-terminal phosphorylation sites of the neighboring subunit, is essential for trimerization. We propose that the phosphorylated C-terminal residues interact with the L3 loop of the neighboring subunit to stabilize the trimer interaction.

Sedimentation studies reveal a direct role of phosphorylation in Smad3:Smad4 homo- and hetero-trimerization.

SMAD proteins are known to oligomerize and hetero-associate during their activation and translocation to the nucleus for transcriptional control. Analytical ultracentrifuge studies on Smad3 and Smad4 protein constructs are presented to clarify the model of homo- and hetero-oligomerization and the role of phosphorylation in the activation process. These constructs all exhibit a tendency to form disulfide cross-linked aggregates, primarily dimers, and a strong reducing agent, TCEP, was found to be required to determine the best estimates for reversible association models and equilibrium constants. A Smad4 construct, S4AF, consisting of the middle linker (L) domain and the C-terminal (C) domain, is shown to be a monomer, while a Smad3 construct, S3LC, consisting of the LC domains, is shown to form a trimer with an affinity K(3) = (1.2-3.1) x 10(9) M(-2). A Smad3 construct that mimics phosphorylation at the C-terminal target sequence, S3LC(3E), has 17--35-fold enhanced ability to form trimer over that of the wild-type construct, S3LC. S4AF associates with either S3LC or S3LC(3E) to form a hetero-trimer. In each case, the hetero-trimer is favored over the formation of the homo-trimer. Despite high sequence homology between Smad3 and Smad4, a chimeric Smad4 construct with an engineered Smad3 C-terminal pseudo-phosphorylation sequence, S4AF(3E), shows no tendency to form trimer. This suggests a Smad4-specific sequence insert inhibits homo-trimer formation, or other domains or sequences in S3LC are required in addition to the target sequence to mediate the formation of trimer. These results represent a direct molecular measure of the importance of hetero-trimerization and phosphorylation in the TGF-beta-activated Smad protein signal transduction process.

Structural basis of Smad1 activation by receptor kinase phosphorylation.

Phosphorylation of Smad1 at the conserved carboxyl terminal SVS sequence activates BMP signaling. Here we report the crystal structure of the Smad1 MH2 domain in a conformation that reveals the structural effects of phosphorylation and a molecular mechanism for activation. Within a trimeric subunit assembly, the SVS sequence docks near two putative phosphoserine binding pockets of the neighboring molecule, in a position ready to interact upon phosphorylation. The MH2 domain undergoes concerted conformational changes upon activation, which signal Smad1 dissociation from the receptor kinase for subsequent heteromeric assembly with Smad4. Biochemical and modeling studies reveal unique favorable interactions within the Smad1/Smad4 heteromeric interface, providing a structural basis for their association in signaling.

A field experiment testing frontline opinion leaders as change agents.

On the basis of previous studies of source credibility and opinion leadership, the authors hypothesized that opinion leaders would serve as effective agents to promote positive attitudes toward a service-quality initiative and increase service-quality effectiveness. The service effectiveness of tellers before and after a service-quality leadership training program was rated by customers, supervisors, and the tellers themselves across 3 matched bank branches. Service effectiveness was rated significantly higher in a branch using opinion leaders as service-quality leaders compared with a branch using randomly selected frontline leaders. Tellers in the latter branch showed greater improvements in service effectiveness than did counterparts in a branch using no frontline service quality leaders. This difference between types of leaders appeared to be mediated by tellers' behavioral beliefs about the service-quality program.

Instrumental values of organizational citizenship behavior for promotion: a field quasi-experiment.

The present study examined the relationship between promotion, perceived instrumentality of organizational citizenship behavior (OCB) for promotion, and employees' OCB before and after promotion. A field quasi-experiment involving 293 tellers of a multinational bank was conducted. Both supervisors and employees provided OCB ratings 3 months before and 3 months after the promotion decision was announced. The authors found employees who perceived OCB as instrumental to their promotion and who were promoted were more likely to decline in their OCB after the promotion.

Collective efficacy versus self-efficacy in coping responses to stressors and control: a cross-cultural study.

This study examined how cultural differences and efficacy perceptions influence the role of job control in coping with job demands. Perceiving higher control mitigated the effects of demands on psychological health symptoms and turnover intentions only among American bank tellers reporting high job self-efficacy. Among American tellers reporting low job self-efficacy, perceived control exacerbated the effects of demands. However, in a matched Hong Kong sample, collective efficacy interacted in the same way with control and demands as job self-efficacy had in the American sample. These differences appear to be explained by the individual attributes of idiocentrism and allocentrism that are linked to the societal norms of individualism and collectivism, respectively.

Improving group decisions by better pooling information: a comparative advantage of group decision support systems.

This study compared a group decision support system (GDSS) with face-to-face (FTF) group discussion on characteristics of information exchange and decision quality. Participants given conflicting information tended to share more of their unique data and engaged in more critical argumentation when using the GDSS than when meeting FTF. Conversely, when information was consistent among members, there were no such differences between FTF and GDSS groups. The GDSS groups significantly outperformed the FTF groups in agreeing on the superior hidden profile candidate, especially when there was a lack of prediscussion consensus. Individual-level analyses revealed that members of GDSS groups that did not have a prediscussion consensus tended to experience stronger preference shifts toward the group's consensus decision.

Lumbar spine kinesthesia in patients with low back pain.

STUDY DESIGN: Single-group, posttest only, using a sample of convenience. OBJECTIVE: To measure the repositioning error of subjects with low back pain for lumbar sagittal movement using a simple kinesthetic test previously described. BACKGROUND: Patients with low back pain are commonly observed to have difficulty in adopting a mid or neutral position of the lumbar spine. METHODS AND MEASUREMENTS: Twenty subjects with low back pain were required to reproduce an upright neutral posture of the lumbar spine following movement into flexion in a sitting position. Trunk positioning accuracy was measured with an electromagnetic tracking device. RESULTS: The mean absolute value of the repositioning error in the sagittal plane was 2.25 degrees +/-0.88 degrees on day 1 and 2.32 degrees +/-1.62 degrees on day 2. The performance of patients with low back pain was similar to that of asymptomatic patients in a previous study, although subjects with low back pain overshot the neutral position more frequently (79%) than did nonimpaired subjects (50%). CONCLUSIONS: Subjects with low back pain may have attempted to use extra mechanoreceptive cues to compensate for some kinesthetic deficit. Nevertheless, the kinesthetic test used was not sensitive enough to detect any repositioning deficits, and reasons for this are explored.

Crystal structure of a transcriptionally active Smad4 fragment.

BACKGROUND: Smad4 functions as a common mediator of transforming growth factor beta (TGF-beta) signaling by forming complexes with the phosphorylated state of pathway-restricted SMAD proteins that act in specific signaling pathways to activate transcription. SMAD proteins comprise two domains, the MH1 and MH2 domain, separated by a linker region. The transcriptional activity and synergistic effect of Smad4 require a stretch of proline-rich sequence, the SMAD-activation domain (SAD), located N-terminal of the MH2 domain. To understand how the SAD contributes to Smad4 function, the crystal structure of a fragment including the SAD and MH2 domain (S4AF) was determined. RESULTS: The structure of the S4AF trimer reveals novel features important for Smad4 function. A Smad4-specific sequence insertion within the MH2 domain interacts with the C-terminal tail to form a structural extension from the core. This extension (the TOWER) contains a solvent-accessible glutamine-rich helix. The SAD reinforces the TOWER and the structural core through interactions; two residues involved in these interactions are targets of tumorigenic mutation. The solvent-accessible proline residues of the SAD are located on the same face as the glutamine-rich helix of the TOWER, forming a potential transcription activation surface. A tandem sulfate-ion-binding site was identified within the subunit interface, which may interact with the phosphorylated C-terminal sequence of pathway-restricted SMAD proteins. CONCLUSIONS: The structure suggests that the SAD provides transcriptional capability by reinforcing the structural core and coordinating with the TOWER to present the proline-rich and glutamine-rich surfaces for interaction with transcription partners. The sulfate-ion-binding sites are potential 'receptors' for the phosphorylated sequence of pathway-restricted SMAD proteins in forming a heteromeric complex. The structure thus provides a new model that can be tested using biochemical and cellular approaches.

Purification and characterization of novel ribosome inactivating proteins, alpha- and beta-pisavins, from seeds of the garden pea Pisum sativum.

Two ribosome inactivating proteins designated alpha- and beta-pisavins were isolated from seeds of the garden pea Pisum sativum var. arvense Poir with a procedure involving affinity chromatography on Affi-gel Blue gel, immobilized metal ion affinity chromatography on Iminodiacetic acid-agarose, cation exchange chromatography on Resource-S, and gel filtration on Superose 12. alpha- and beta-pisavins are nonglycoproteins with a molecular weight of 20.5 kDa and 18.7 kDa respectively. The sequences of the first sixty N-terminal amino acids of alpha- and beta-pisavins were identical. In isoelectric focusing these two proteins merged into one band with a pI greater than 9.3. Inhibition of protein synthesis by a rabbit reticulocyte lysate system was achieved at an IC50 of approximately 0.5 nM. Activity of the proteins toward tRNA was observed. The proteins acted on ribosomal RNA through its RNA N-glycosidase activity to release an Endo's fragment, and converted the conformation of DNA from supercoiled and circular forms into a linear form.

Nonlinear pharmacokinetics of 5-fluorouracil in rats.

The effects of dose on the pharmacokinetics of 5-fluorouracil (5-FU) were investigated following intravenous administration of 5-FU at 10, 50, and 100 mg/kg to adult male Sprague-Dawley rats. Six rats were studied at each dose level. The dose-normalized area under the curve (AUC) was significantly higher after administration of 100 mg/kg (1.14 +/- 0.55 mg.h/L/mg; mean +/- SD) than after 50 mg/kg (0.50 +/- 0.18 mg.h/L/mg) or 10 mg/kg (0.43 +/- 0.11 mg.h/L/mg), indicating nonlinear elimination of 5-FU in rats. Dose- and time-average pharmacokinetic parameters were calculated by area/moment analysis. The systemic clearance of 5-FU following administration of 100 mg/kg was significantly lower (1.1 +/- 0.49 L/h/kg) than after 50 mg/kg (2.2 +/- 0.72 L/h/kg) or 10 mg/kg (2.4 +/- 0.67 L/h/kg). There was no significant difference in renal clearance values between the three doses (0.47 +/- 0.26 L/h/kg). However, nonrenal clearance was significantly lower after the 100-mg/kg dose (0.77 +/- 0.2 L/h/kg) than after the 50-mg/kg (1.65 +/- 0.49 L/h/kg) and 10-mg/kg (1.87 +/- 0.75 L/h/kg) doses. There was no significant difference between the steady-state volume of distribution values (0.91 +/- 0.36 L/kg) at the three doses. The lower nonrenal clearance following the 100-mg/kg dose compared with that after the lower doses of 5-FU suggested nonlinear metabolism of 5-FU in rats. A two-compartment pharmacokinetic model with parallel first-order (renal excretion) and Michaelis-Menten elimination from the central compartment was simultaneously fit to mean plasma 5-FU concentration versus time data for the three doses. The maximum volume (Vmax) and Michaelis constant (Km) values averaged (mean +/- SE) 8.3 +/- 2.3 mg/h and 31.6 +/- 11.9 mg/L, respectively. The information obtained in this study will be valuable for the evaluation of prodrugs of 5-FU that are designed to reduce toxicities and to improve oral bioavailability of the anticancer agent.