Paenibacillus exopolysaccharide alleviates Malassezia-induced skin damage: Enhancing skin barrier function, regulating immune responses, and modulating microbiota.

Numerous studies have established a strong association between Malassezia and various skin disorders, including atopic dermatitis. Finding appropriate methods or medications to alleviate Malassezia-induced skin damage is of notable public interest. This study aimed to evaluate the therapeutic effect of the exopolysaccharide EPS1, produced by Paenibacillus polymyxa, on Malassezia restricta-induced skin damage. In vitro assays indicated that EPS1 reduced the expression of pro-inflammatory cytokine genes in TNF-α-induced HaCaT cells. In a murine model, EPS1 was found to mitigate clinical symptoms, reduce epidermal thickness and mast cell infiltration, improve skin barrier function, decrease pro-inflammatory cytokine levels associated with type 17 inflammation, enhance Tregs in the spleen, upregulate the transcription of Treg-related genes in skin lesions, and modulate the skin microbiota. This study is the first to report the alleviating effect of Paenibacillus exopolysaccharide on Malassezia-induced skin inflammation and its impact on the skin microbiota. These findings support the potential of Paenibacillus exopolysaccharides as consumer products and therapeutic agents for managing Malassezia-induced skin damage by improving skin barrier function, modulating immune responses, and influencing skin microbiota.

Thalidomide Combined with Chemotherapy in Treating Patients with Advanced Colorectal Cancer.

OBJECTIVE: To assess the safety and effectiveness of thalidomide (produced by CHANGZHOU PHARMACEUTICAL FACTORY CO.LTD) combined with chemotherapy in treating patients with advanced colorectal cancer. METHOD: A consecutive cohort of pretreated patients with advanced colorectal cancer were treated with thalidomide combined with chemotherapy. And chemotherapy for patients with advanced colorectal cancer were administered according to the condition of patients. Thalidomide was orally administered at a dosage of 50mg/day to 150 mg/day before sleeping for at least 14 days. After at least 14 days of treatment, safety and side effects were evaluated. RESULTS: There were 12 female and 3 male patients with advanced cancer recruited into this study, including 9 patients with colon, 6 patients with rectal cancer. The median age of patients was 57(41- 82) years. Partial response was observed in 2 patients (2/15), and stable disease in 3 patients(3/15). Incidences of Grade 1 to 2 myelosuppression was observed in 1/15 patients, and Grade 1 to 2 elevation of hepatic enzyme was recorded in 1/15 patients. Adverse effects on the gastrointestinal tract were documented in 1/15 patients, and were Grade 1. No Grade 3-4 toxicities were diagnosed. No treatment related death was found. CONCLUSIONS: Thalidomide combined with chemotherapy was safe and mildly effective in treating patients with advanced colorectal cancer. However, further study should be conducted to clarify the effectiveness of this combination.

Relationship between p53 status and response to chemotherapy in patients with gastric cancer: a meta-analysis.

BACKGROUND: Previous studies have yielded conflicting results regarding the relationship between p53 status and response to chemotherapy in patients with gastric cancer. We therefore performed a meta-analysis to expound the relationship between p53 status and response to chemotherapy. METHODS/FINDINGS: Thirteen previously published eligible studies, including 564 cases, were identified and included in this meta-analysis. p53 positive status (high expression of p53 protein and/or a mutant p53 gene) was associated with improved response in gastric cancer patients who received chemotherapy (good response: risk ratio [RR] = 0.704; 95% confidence intervals [CI] = 0.550-0.903; P = 0.006). In further stratified analyses, association with a good response remained in the East Asian population (RR = 0.657; 95% CI = 0.488-0.884; P = 0.005), while in the European subgroup, patients with p53 positive status tended to have a good response to chemotherapy, although this did not reach statistical significance (RR = 0.828, 95% CI = 0.525-1.305; P = 0.417). As five studies used neoadjuvant chemotherapy (NCT) and one used neoadjuvant chemoradiotherapy (NCRT), we also analyzed these data, and found that p53 positive status was associated with a good response in gastric cancer patients who received chemotherapy-based neoadjuvant treatment (RR = 0.675, 95% CI = 0.463-0.985; P = 0.042). CONCLUSION: This meta-analysis indicated that p53 status may be a useful predictive biomarker for response to chemotherapy in gastric cancer. Further prospective studies with larger sample sizes and better study designs are required to confirm our findings.

[Effect of regulation of Y-box protein 1 by RNA interference on the doxorubicin induced mdr1 gene expression in K562 cells].

OBJECTIVE: To investigate the effect of YB-1 on the transcription of induced mdr1 gene expression in K562 cells. METHODS: K562 cells were treated with doxorubicin (DOX) at different concentrations and times. Expression of mdr1 and YB-1 genes was examined by RT-PCR and P-glycoprotein (P-gp) by flow cytometry. Cyto/nuclear protein was extracted for YB-1 detection by Western blotting. The expression of YB-1 gene in K562 cells was inhibited by YB-1 gene specific RNA interference (RNAi), then the expression of mdr1 and P-gp in YB-1 gene silenced cells treated with DOX was detected. RESULTS: The mdr1 gene as well as its corresponding protein P-gp was highly expressed in DOX exposed K562 cells. DOX up-regulated the expression of YB-1 gene, and promoted YB-1 protein nuclear translocation. On YB-1 gene silenced, the expressions of mdr1 gene and P-gp were obviously down-regulated in DOX treated K562 cells. CONCLUSION: Doxorubicin can induce the expression of mdr1 gene in K562 cells, which may result from the transcription of mdr1 gene by activated YB-1.

[Effect of desferrioxamine on K562/A02 cell line and its mechanism].

Iron is an essential element for cell growing including tumor cells. This study was purposed to explore the effect of desferrioxamine (DFO) on cell line K562/A02 and its mechanism. K562/A02 cells were cultured with different concentrations of DFO. The inhibitory effects of adriamycin (ADM) used alone or combined with DFO on the proliferation of K562/A02 was evaluated by MTT assay. The apoptosis rate of K562/A02 cells after treatment with 0, 12.5, 25 and 50 µmol/L DFO alone or in combination with 1 mg/L ADM were analyzed by flow cytometry. ADM accumulation in K562/A02 cells after treatment with different concentrations of 0, 12.5, 25 and 50 µmol/L DFO were also analyzed by flow cytometry. The levels of BAX/BCL-2 and MDR1 mRNA were determined by RT-PCR, and then the protein level of P-glycoprotein (P-gp) was detected by Western blot. The results showed that the IC(50) of ADM for K562 and K562/A02 cells were (1.46 ± 0.07) mg/L and (40.98 ± 3.05) mg/L respectively. The resistance of K562/A02 cells to ADM was 28.06 times as that of K562 cells. After treatment of K562/A02 cell with DFO of 12.5, 25 and 50 µmol/L for 48 hours, the resistance of K562/A02 cells to ADM were increased by 24.95, 16.11 and 9.99 times respectively. When K562/A02 cells were incubated with different concentrations of DFO of 12.5, 25, 50 µmol/L for 48 hours, the apoptosis rat were (3.50 ± 0.30)%, (7.27 ± 0.32)% and (12.53 ± 1.21)% respectively. After co-culture with DFO and ADM for 48 hours, apoptosis rate were (6.13 ± 0.29)%, (9.57 ± 0.40)% and (18.97 ± 1.10)% respectively. The above apoptosis rates was much higher than that of control group (p < 0.05) and they were dose-dependent. In comparison between DFO + ADM group and DFO group, there was no significant difference (p > 0.05). Expression rate of BAX/BCL-2 increased. The levels of MDR1 mRNA reduced. Furthermore, expression of P-gp also decreased in K562/A02 cells. It is concluded that iron increase can promote K562/A02 cells growth and inhibit their apoptosis. Otherwise, iron-deprivation can induce K562/A02 cells apoptosis. DFO disturbs the iron metabolism and inhibits DNA synthesis of K562/A02 cells. This action of DFO may enhance the susceptibility of K562/A02 cells to apoptosis induced by chemotherapeutic drugs. The iron-deprivation may play a role in the treatment of leukemia with combination of DFO with other anticancer agents.

[Influence of YB-1 protein on the biological behaviour in K562/A02 cells].

The aim of this study was to investigate whether the growth, apoptosis and sensitivity to anticancer agent could be altered after introduction of YB-1 shRNA eukaryotic expression vector into the K562/A02 cells, and its possible molecular mechanisms. The recombinant eukaryotic expression plasmids including YB-1 shRNA and the vector-random-sequence were introduced into K562/A02 cells by lipofectamine mediation, and the positive clones were screened by G418. RT-PCR and Western blot were employed to detect the expression of mRNA and protein of YB-1 in leukemia cells, respectively. The proliferative ability of the cells was determined by MTT assay and cell cycle analysis. Apoptosis of K562/A02 cells was assayed by AnnexinV-FITC/PI double labeled flow cytometry. The drug sensitivity to anticancer agent was determined by MTT assay. The expressions of MDR1 gene and P-gp were detected by RT-PCR and flow cytometry respectively. The results indicated that the levels of mRNA and protein of YB-1 decreased dramatically in three groups of positively transfected cells when compared with control cells. The inhibitory rates of 3 different shRNA sequences targeting YB-1 gene were (65.1 ± 2.1)%, (27.4 ± 1.3)% and (67.4 ± 1.6)% respectively. The introduction of exogenous YB-1 shRNA gene into K562/A02 cells resulted in decreased levels of the proliferative ability in K562/A02 cells, and displayed higher at G(1), lower at G(2) and S phase in cell cycle distribution in comparison with the control groups. AnnexinV/PI detection indicated higher AnnexinV(+) ratio in 3 groups of positively transfected cells after being treated with As(2)O(3) of 0.5 µmol/L for 24 hours. The IC(50) values of doxorubicin in 3 groups of positively transfected cells were significantly lower than that in control group. The level of MDR1 gene and P-gp decreased significantly in 3 groups of positively transfected cells. It is concluded that the transfection with YB-1 shRNA gene can inhibit the proliferation of leukemia cells and induce cell apoptosis. The expression of MDR1 mRNA and P-gp decrease after transfection of YB-1 shRNA into K562/A02 cells.

[Effects of 5-bromotetrandrine and daunorubicin on apoptosis and expression of survivin in K562/A02 cells].

The aim of this study was to investigate the potential benefit of combination therapy with 5-bromotetrandrine (5-BrTet) and daunorubicin (DNR) on chronic leukemia. The apoptosis of K562/A02 cells treated by DNA, BrTet and BrTet combined with DNR for 48 hours was detected by flow cytometry; the expressions levels of survivin mRNA and protein K562/A02 cells treated by DNR, BrTet and BrTet combined with DNR and in untreated K562 cells for 48 hours were measured by RT-PCR and Western blot respectively. The results showed that the combination of BrTet with DNR increased apoptotic rate of K562/A02, down-regulated the expression levels of survivin mRNA and protein in K562/A02 cells as compared with blank control and cells treated by BrTet or DNR alone, the survivin expression in K562/A02 cells was higher than that in K562 cells. It is concluded that the combination of BrTet with DNR can effectively reverse the multidrug resistance of K562/A02 cells, promote the apoptosis of K562/A02 cells, the mechanism of which may be related with down-regulation of survivin expression. Survivin may be a target for the treatment of MDR in hematopoietic malignancies.

[VEGF shRNA enhances the sensitivity of multidrug-resistant leukemia cells to anticancer agent].

This study was aimed to explore the effect of vascular endothelial growth factor (VEGF) on sensitivity of leukemia cell line K562/A02 to doxorubicin by using RNA interference, and to investigate its mechanism. The 3 shRNA targeting human vegf gene were synthesized, then transfected into K562/A02 cells by lipofectamine 2000 reagent. RT-PCR was used to detect the expression of vegf and mrp1 at the mRNA level;Western blot was used to analyze the expression of VEGF, MRP1, AKT, P-AKT at the protein level; MTT was used to determine the IC(50) value of transfected cells to doxorubicin (DOX); flow cytometry was used to detect cell apoptosis and intracellular Rho123 retention. The results showed that after vegf shRNA were transfected into K562/A02 cells, the expression of vegf at the mRNA level decreased, and the difference between vegf shRNA2 group or vegf shRNA3 group and HK group was statistically significant (p < 0.05), the greatest decrease was observed in the cells transfected with vegf shRNA3; and the protein level of VEGF was also down-regulated. The IC(50) value of positively transfected group was lower than that of control groups, and the difference between vegf shRNA2 group or vegf shRNA3 group and HK group was significant (p < 0.05). The retention of intracellular Rho123 was enhanced in three positively transfected groups (p < 0.05). Cell apoptosis increased in positively transfected groups, and there was statistically difference between vegf shRNA2 group or vegf shRNA3 group and HK group (p < 0.05). The expression of mrp1 at the mRNA level were decreased, and there were statistical difference between vegf shRNA3 group and HK group (p < 0.05), and the protein level of mrp1 was also down-regulated; the expression of P-AKT at protein level decreased in positively transfected groups, and the greatest decrease was seen in vegf shRNA3 group. It is concluded that the transfection with exogenous vegf shRNA can inhibit the expression of vegf at both mRNA and protein levels, and enhance the sensitivity of K562/A02 cell to doxorubicin, the mechanism of which may be the inhibition of apoptosis and down-regulation of MRP1 by inactivating PI3K/AKT signaling pathway.

Preventing chemoresistance of human breast cancer cell line, MCF-7 with celecoxib.

PURPOSE: To investigate the preventive effect of celecoxib, a specific cyclooxygenase-2 (Cox-2) inhibitor, on the development of chemoresistance in breast cancer cell line, MCF-7, and explore the mechanism of the action. METHODS: Chemoresistance phenotype was established by treating MCF-7 cells with 0.05 µg/ml doxorubicin for 7 days, and then the effect of preventive chemoresistance was investigated by the combination of same dose of doxorubicin with 10 µM celecoxib. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay was used to assess cytostatic efficacy of doxorubicin and 50% inhibiting concentration (IC(50)) of MCF-7 cells. RT-PCR was performed to examine mRNA expression of multidrug resistance gene 1 (MDR1) and its transcription factors c-Jun and NF-κB. Western blotting analysis was performed to detect the expression of protein. Flow cytometry (FCM) was applied to analyze the expression and function of P-glycoprotein (P-gp). Electrophoretic gel mobility shift assay (EMSA) was performed to determine the DNA-binding activity of nuclear transcription factors AP-1 and NF-κB. RESULTS: Compared with sensitive MCF-7 cells, MDR1 and its transcription factors c-Jun and NF-κB were up-regulated at both mRNA level (P < 0.01) and protein level (P < 0.01) by treatment with 0.05 µg/ml doxorubicin for 7 days. After co-incubation with both the same dose of doxorubicin and 10 µM celecoxib for 7 days, both mRNA level and protein level of MDR1, c-Jun and NF-κB up-regulated by doxorubicin were partly reversed (P < 0.01); DNA-binding activity of nuclear transcription factors AP-1 and NF-κB were inhibited; and the function of P-gp was decreased (P < 0.01). When MCF-7 cells were treated with increasing doses of doxorubicin in the presence of 10 µM celecoxib, IC50 value of doxorubicin and doxorubicin plus 10 µM celecoxib was 0.67 ± 0.03 and 0.38 ± 0.04 µg/ml, respectively (P < 0.01). CONCLUSION: Celecoxib effectively prevents the development of chemoresistance in breast cancer cell line MCF-7 induced by doxorubicin, which was partly involved in inhibiting the expression and DNA-binding activity of nuclear transcription factors AP-1 and NF-κB and downstream expression and function of P-gp. Furthermore, cytostatic efficacy of celecoxib and doxorubicin on MCF-7 cell was synergistic.