Pseudomonas Aeruginosa-mannose-sensitive Hemagglutinin Research Articles

Trends in Anti-Tumor Effects of Pseudomonas aeruginosa Mannose-Sensitive-Hemagglutinin (PA-MSHA): An Overview of Positive and Negative Effects

Cancer is a leading cause of death worldwide, for which finding the optimal therapy remains an ongoing challenge. Drug resistance, toxic side effects, and a lack of specificity pose significant difficulties in traditional cancer treatments, leading to suboptimal clinical outcomes and high mortality rates among cancer patients. The need for alternative therapies is crucial, especially for those resistant to conventional methods like chemotherapy and radiotherapy or for patients where surgery is not possible. Over the past decade, a novel approach known as bacteria-mediated cancer therapy has emerged, offering potential solutions to the limitations of conventional treatments. An increasing number of in vitro and in vivo studies suggest that the subtype of highly virulent Pseudomonas aeruginosa bacterium called Pseudomonas aeruginosa mannose-sensitive-hemagglutinin (PA-MSHA) can successfully inhibit the progression of various cancer types, such as breast, lung, and bladder cancer, as well as hepatocellular carcinoma. PA-MSHA inhibits the growth and proliferation of tumor cells and induces their apoptosis. Proposed mechanisms of action include cell-cycle arrest and activation of pro-apoptotic pathways regulated by caspase-9 and caspase-3. Moreover, clinical studies have shown that PA-MSHA improved the effectiveness of chemotherapy and promoted the activation of the immune response in cancer patients without causing severe side effects. Reported adverse reactions were fever, skin irritation, and pain, attributed to the overactivation of the immune response. This review aims to summarize the current knowledge obtained from in vitro, in vivo, and clinical studies available at PubMed, Google Scholar, and ClinicalTrials.gov regarding the use of PA-MSHA in cancer treatment in order to further elucidate its pharmacological and toxicological properties.

Efficacy of anti-PD-1 monoclonal antibody combined with bevacizumab and/or Pseudomonas aeruginosa injection in transplanted tumor of MFC gastric cancer in mice and its mechanism in regulating tumor immune microenvironment.

Tumor immunotherapy represented by PD-1 inhibitors is considered as the most promising cancer treatment method and has been widely used in the treatment of advanced gastric cancer (GC). However, the effective rate of PD-1 inhibitor monotherapy is low. In this study，we constructed a transplanted tumor model in GC mice by inoculating mouse MFC GC cells into 615 mice. Interventions were conducted with normal saline, anti-PD-1 monoclonal antibody (mAb), bevacizumab, PA-MSHA, anti-PD-1 mAb combined with bevacizumab, anti-PD-1 mAb combined with PA-MSHA, bevacizumab combined with PA-MSHA, anti-PD-1 mAb combined with bevacizumab and PA-MSHA, respectively. The tumor growth curves were drawn. Tunel assay, Western blotting and immunohistochemistry were used to detect tumor proliferation and apoptosis. Flow cytometry and Elisa were used to detect the expression of tumor infiltrating lymphocytes and cytokines.This study found that anti-PD-1 mAb alone could not significantly inhibit the growth of transplanted tumors in mice. Anti-PD-1 mAb combined with bevacizumab, anti-PD-1 mAb combined with PA-MSHA, anti-PD-1 mAb combined with bevacizumab and PA-MSHA could all significantly inhibit tumor growth in mice, and the combination of three drugs presented the highest tumor inhibition rate. Anti-PD-1 mAb combined with bevacizumab and PA-MSHA could significantly up-regulate the number of Th1-type cells, CD8+T cells and type I TAMs, while down-regulate the number of Th2-type cells, MDSCs, Tregs and type II TAMs.Therefore, we conclude that anti-PD-1 mAb combined with bevacizumab and/or PA-MSHA has a synergistic effect. Bevacizumab and PA-MSHA can transform the tumor immunosuppressive microenvironment into a supportive immune microenvironment, thus maximizing the anti-tumor effect of anti-PD-1 mAb.

Regulatory effect of Pseudomonas aeruginosa mannose-sensitive hemagglutinin on inflammation and immune function in percutaneous nephrolithotomy patients with upper urinary tract calculi complicated with infection.

To study the effect of an injection of Pseudomonas aeruginosa mannose-sensitive hemagglutinin (PA-MSHA) on inflammation and immune function in patients with upper urinary tract calculi complicated by infection who have undergone percutaneous nephrolithotomy. We retrospectively recorded the clinical data of patients with upper urinary tract calculi complicated by infection who have undergone Percutaneous nephrolithotomy(PCNL) in the Department of Urology, 2nd Affiliation Hospital of Kunming Medical University, from March to December 2021. Clinical data include general condition, laboratory index, CT, postoperative body temperature, heart rate, respiration, SIRS, sepsis, etc. Patients were divided into treated and control groups according to whether they had received a preoperative PA-MSHA injection. The two groups were compared for indices of inflammation and complications of infection after PCNL. Pre- and post-operative lymphocyte subsets and immunoglobulin changes were compared. 115 patients were included in the study, including 43 in the treatment group and 72 in the control group. After Propensity Score Matching, 90 patients were divided into treatment (n=35) and control (n=55) groups. The postoperative inflammation index was higher in the treatment group than in the control group (P<0.05). The incidence of postoperative SIRS was higher in the treatment group than control (P<0.05). There were no cases of sepsis in either group. The double-positive T cells lymphocyte subsets were higher in the treatment group than in the control group ((P<0.05). Pre- and post-operative changes in immune function: total T lymphocyte count reduced, NK and NKT cell count increased in the control group, double-positive T cell count increased in the treatment group, IgG, IgA, IgM, complement C3 and C4 count reduced in both groups post-operatively. This study found that patients with upper urinary tract calculi and infection treated with antibiotic-based PA-MSHA before percutaneous nephrolithotomy had an increased inflammatory response after surgery, which may play a role in the prevention and treatment of sepsis. The percentage of double-positive T cells in the peripheral blood was increased after PA-MSHA treatment, which may have an immunomodulatory and protective effect in PCNL patients with stones complicated by infection.

Neoadjuvant Pseudomonas aeruginosa mannose-sensitive hemagglutinin (PA-MSHA) and chemotherapy versus placebo plus chemotherapy in patients with HER2-negative breast cancer: a randomized, controlled, double-blind trial.

According to preclinical experiments, Pseudomonas aeruginosa mannose-sensitive hemagglutinin (PA-MSHA) exerts antiproliferative effects against breast cancer cells. It has been approved by the State Food and Drug Administration in China for complementary cancer treatment, and its safety has been confirmed in previous clinical trials. The present randomized, controlled, double-blind clinical trial was conducted to investigate the efficacy and safety of neoadjuvant PA-MSHA and placebo with chemotherapy in patients with human epidermal growth factor receptor 2 (HER2)-negative breast cancer. Eligible patients aged 18 years or older with previously untreated HER2-negative stage II-III breast cancer were enrolled and randomly assigned at a 1:1 ratio to receive neoadjuvant chemotherapy with PA-MSHA or a placebo. The Response Evaluation Criteria in Solid Tumors (RECIST) was used to assess clinical response every 2 cycles. The primary endpoint was the objective response rate (ORR) based on the clinical response following neoadjuvant chemotherapy. A total of 75 patients were randomly assigned to either the PA-MSHA group (37 patients) or the control group (38 patients). The ORR was found to be significantly higher in the PA-MSHA group compared with the control group [86.5% versus 60.5%; rate difference 26.0; 95% confidence interval (CI): 5.9-43.5%; P=0.011]. The pathological complete response (pCR) and survival outcomes did not differ significantly between the 2 groups. Patients with immune-related adverse events (irAEs) appeared to benefit from the PA-MSHA treatment, with greater disease-free, relapse-free, and overall survival. The application of PA-MSHA to neoadjuvant chemotherapy did not increase the incidence of severe adverse events. Moreover, the addition of PA-MSHA increased serum interferon-γ levels and the percentage of peripheral blood T cells, CD8+/CD4+ T cells, CD8+CD28+ T cells, and natural killer (NK) cells, and decreased serum interleukin 4 levels. The addition of PA-MSHA to neoadjuvant chemotherapy is an effective alternative regimen for HER2-negative breast cancer. Patients with irAEs caused by PA-MSHA may obtain more benefits from this treatment. Chinese Clinical Trial Registry ChiCTR-TRC-10000794.

PA-MSHA Regulates PD-L1 Expression in Hepatoma Cells

ABSTRACT Background Programmed death ligand 1 (PD-L1) is expressed in hepatocellular carcinoma (HCC) cells. PD-L1 function and structure are regulated through glycosylation and various signaling pathways. However, the relationship between Pseudomonas aeruginosa mannose sensitive hemagglutinin (PA-MSHA), glycosylation and PD-L1 warrants further study. In this study, we investigated the effects of PA-MSHA on the regulation of mannosyl and N-glycosylation to identify the mechanisms underlying its function. Methods PD-L1, β-catenin, c-Myc, mannosyl, MGAT1 and mannosidase II in HCC were identified by postoperative specimens from the HCC cohort with immunohistochemistry and immunofluorescence. PA-MSHA was used to suppress tumor progression. Alterations to the expression of PD-L1, β-catenin, c-Myc, MGAT1, and mannosidase II at the gene and protein levels were detected by qRT-PCR and Western blot analysis. Soluble PD-L1 (sPD-L1) were detected using enzyme-linked immunosorbent assay. Results Mannosyl and mannosidase II expression levels increased, whereas those of MGAT1 decreased in the HCC cells. The glycosylation-related pathway proteins, namely, β-catenin, c-Myc and PD-L1, had increased expression levels. Moreover, proliferation in the HCC cells was inhibited after PA-MSHA treatment, PD-L1 function was significantly inhibited. Transmission electron microscopy showed that PA-MSHA penetrated into the HCC cytoplasm through the cytomembrane, resulting in apoptosis. Here, PA-MSHA significantly reduced sPD-L1 expression levels in the tumor cells. Conclusions PA-MSHA plays the role of a lectin, affecting receptors on the cytomembrane. This strain inhibits mannosyl by suppressing β-catenin signaling. We hypothesized that PA-MSHA suppresses PD-L1 by: 1. Inhibiting the glycosylation process; and 2. Suppressing β-catenin and c-Myc, thereby reducing the transcription of this protein.

PA-MSHA induces inflamed tumor microenvironment and sensitizes tumor to anti-PD-1 therapy

A low response rate to immune checkpoint inhibitor (ICI) therapy has impeded its clinical use. As reported previously, an inflamed tumor microenvironment (TME) was directly correlated with patients’ response to immune checkpoint blockade (ICB). Thus, restoring the cytotoxic effect of immune cells in the TME is a promising way to improve the efficacy of ICB and overcome primary resistance to immunotherapy. The effect of Pseudomonas aeruginosa mannose-sensitive-hemagglutinin (PA-MSHA) in facilitating T cell activation was determined in vitro and in vivo. Subsets of immune cells were analyzed by flow cytometry. Proteomics was carried out to comprehensively analyze the discriminated cellular kinases and transcription factors. The combinational efficacy of PA-MSHA and αPD-1 therapy was studied in vivo. In this study we demonstrated that PA-MSHA, which is a clinically used immune adjuvant, effectively induced the anti-tumor immune response and suppressed the growth of non-small cell lung cancer (NSCLC) cells. PA-MSHA showed great potential to sensitize refractory “cold” tumors to immunotherapy. It effectively enhanced macrophage M1 polarization and induced T cell activation. In vivo, in combination with αPD-1, PA-MSHA suppressed tumor growth and prolonged the survival time of allograft model mice. These results indicate that PA-MSHA is a potent agent to stimulate immune cells infiltration into the TME and consequently induces inflammation in tumors. The combination of PA-MSHA with αPD-1 is a potential strategy to enhance the clinical response rate to ICI therapy.

Analysis of factors influencing postoperative drainage time in breast cancer.

To investigate the related factors affecting the postoperative indwelling time of drainage tubes (hereinafter referred to as drainage time) in breast cancer (BC) and evaluate the effect of Pseudomonas aeruginosa-mannose-sensitive hemagglutinin (PA-MSHA) preparation on reducing postoperative drainage time. The clinical data of 165 BC patients in our hospital, including the postoperative drainage time and occurrence of seroma and related complications (such as fever, incision infection, and flap necrosis) after extubation, were retrospectively analyzed. Univariate, multivariate, and stratified analyses were used to determine the correlations between 15 factors including age, body weight, body mass index (BMI), and PA-MSHA preparation, and the postoperative total drainage volume and drainage time. Age, BMI, and PA-MSHA preparation were independent factors affecting the postoperative drainage volume and drainage time of BC patients. Age and BMI were positively correlated with postoperative drainage volume and drainage time (P≤0.004, P≤0.037). PA-MSHA preparation significantly reduced the postoperative total drainage volume and drainage time (P<0.001), decreased the incidence of seroma after extubation (P=0.024), and did not increase complications (P>0.05). Obese and elderly patients were at a significantly high risk of a high drainage volume and long drainage time. Local treatment with PA-MSHA preparation had the advantages of reducing postoperative drainage volume, reducing drainage time, preventing seroma, and not increasing complications, and was a safe and effective treatment. For BC patients aged over 60 years and with a BMI ≥25, the intraoperative local spraying of wounds with PA-MSHA preparation to reduce postoperative drainage times is a valuable option.

Pseudomonas aeruginosa-mannose-sensitive hemagglutinin inhibits chemical-induced skin cancer through suppressing hedgehog signaling

Pseudomonas aeruginosa-mannose-sensitive hemagglutinin (PAM) is an inactivate P. aeruginosa with mannose-sensitive hemagglutinin. Recently, the anticancer properties of PAM against many cancers have been reported across a range of studies. However, the exact mechanism through which PAM prevents skin cancer remains unclear. The aim of this study is to show to what extent PAM could inhibit the dimethylbenzanthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA)-induced skin cancer. JB6 cells were treated by TPA so as to establish an in vitro model. The effects of PAM on proliferation of the cells were analyzed using cell counting kit-8 assays. Effects on epithelial–mesenchymal transition (EMT) were assayed by real-time PCR and Western blotting. A DMBA/TPA-induced skin cancer mouse model was also established. The results showed that TPA promoted EMT changes through the activation of the hedgehog (Hh) pathway, which was reversed by PAM. Moreover, PAM inhibited the cancer growth and Hh pathway in vivo. These data indicate that PAM may serve as a potential anticancer agent for the treatment of skin cancer. Impact statement Pseudomonas aeruginosa-mannose-sensitive hemagglutinin (PAM) restrained the chemical-induced skin cancer cells in vitro and in vivo partly through suppressing the Hh signaling pathway, indicating that PAM may be a promising anticancer agent for treating skin cancer.

Pseudomonas aeruginosa-mannose sensitive hemagglutinin injection therapy for the treatment of chyle fistula following neck dissection.

The efficacy of Pseudomonas aeruginosa-mannose sensitive hemagglutinin (PA-MSHA) injection therapy in the treatment of chyle fistula following neck dissection is unclear. This prospective study enrolled 26 patients who developed chyle fistula after neck dissection. Patients were divided into high-output (>500 mL) and low-output groups (≤500 mL) and were initially treated conservatively for 5 days in the high-output group or 7 days in the low-output group. When conservative treatment failed, topical PA-MSHA therapy was applied. Twelve of 26 patients were cured with conservative treatment, and the remaining 14 patients were all successfully resolved by PA-MSHA therapy. Chyle fistula got resolved in the low-output and high-output groups after the initiation of therapy were at a median 1 days and 6 days, respectively. Among them, 12 (85.7%) patients experienced fever and 11 (78.6%) patients experienced neck pain. Topical PA-MSHA injection therapy could effectively manage chyle fistula following neck dissection.

Inactivated P. aeruginosa restores immune imbalance of chronic idiopathic urticaria.

The main pathology involved in chronic idiopathic urticaria (CIU) is immunological dysfunction which mainly adapts to the immune system of body. Pseudomonas aeruginosa-mannose-sensitive hemagglutinin (PA) is an inactivated Pseudomonas aeruginosa biological product which displays a broad immune regulatory effect. The current study was designed to explore the protective nature of PA as an immune regulator in CIU. The participants were randomly divided into CIU + PA, CIU, control + PA and control group. lg E, anti FcεRI, anti IgE antibody, IL-4, IL-17, TGF-β1 and interferon-γ in the sera were assayed by ELISA. Then CD4+ T cells and CD19+ B cells were isolated from peripheral blood of patients with CIU (n = 10) and healthy control (n = 10). CD4+ T cells and CD19+ B proliferation and apoptosis were analyzed through CCK-8 and flow cytometry respectively. T helper cells differentiations were assessed by real-time PCR. The results revealed that compared with the control group, the curative effect of CIU + PA group was more effective than that of the CIU control group. There was a hyper proliferation of CD19+ B cells in the CIU patients. Moreover, it was also discovered that presence of Th1 decreased while Th2 cells increased in CIU patients. PA significantly inhibited the proliferation of CD19+ B and Th2 cells but at the same time promoted the proliferation of Th1 compared to healthy control. The conclusion arrived at from this study is that the PA displayed a remarkable regulatory effect in CD4+ T cells and CD19+ B cells function by promoting Th1 but inhibited Th2 and the hyperfunction of B cells of CIU patients.

PA-MSHA induces apoptosis and suppresses metastasis by tumor associated macrophages in bladder cancer cells

BackgroundThe aim of the present study was to investigate effects of Pseudomonas aeruginosa-mannose-sensitive hemagglutinin (PA-MSHA) on the inhibition of the proliferation of bladder cancer cell lines and to further define its functional mechanisms.MethodsA rat model of bladder tumor was induced by intravesical N-methyl-N nitrosourea. The dynamic growth of tumor was measured by whole-body fluorescent imaging system. Morphological analysis was observed by hematoxylin–eosin staining and microscopic examination. The expression of Caspase 3 and E-Ca were detected by immunohistochemistry technique. Macrophages were separated by flow cytometry. The expression of cytokines was measured by qRT-PCR and western blot. Apoptosis ability was conducted by means of annexin V and propidium iodide. The abilities of invasion and migration were determined by transwell migration assay and scratch assay.ResultsPA-MSHA and PA-MSHA + Fisetin groups inhibited the growth of tumor and increased the ratio of M1/M2. For one thing, PA-MSHA suppressed the invasive ability of the bladder tumor cell and promoted bladder tumor cell apoptosis. For another, it facilitated the expression of M1 cytokines and reduced expression of M2 cytokines. Furthermore, treated with PA-MSHA, mouse M1 phagocytosis rates were higher than that of M2 macrophages for bladder cancer lines.ConclusionsThe data revealed that PA-MSHA might promote apoptosis and inhibit proliferation, invasion and migration of mouse bladder cancer cells by inducing M1 polarization.

Pseudomonas aeruginosa-mannose sensitive hemagglutinin injection treated cytokine-induced killer cells combined with chemotherapy in the treatment of malignancies

Pseudomonas aeruginosa-mannose sensitive hemagglutinin (PA-MSHA) injection serves as immunological adjuvant in clinical treatment of cancer patients. In present study, we investigated whether PA-MSHA injection enhanced the anti-tumor efficacy of CIK cells. Twenty patients with malignancies were enrolled in this retrospective clinical trial. They were divided into two groups: 10 patients received PA-MSHA treated CIK cells transfusion combined with chemotherapy, and other patients accepted CIK cells and chemotherapy. The efficacy of PA-MSHA treated CIK cells was also observed in vitro and in vivo. With PA-MSHA treatment CIK cells exhibited enhanced proliferation but decreased expression of inhibitory cell surface markers such as Tim-3 and PD-1. Particularly in CIK cells, PA-MSHA promoted the extrusion of pro-inflammatory cytokines like IFN-γ. Of 10 patients with PA-MSHA treated CIK cells and chemotherapy, two patients reached partial remissions, 7 patients had stable disease and the other one had progressive disease. Some of these patients experienced fever after cell infusion. 8 patients with CIK cells showed stable disease and 2 patients had progressive disease. Moreover, the side effects were small in patients with CIK treatment. Our data indicated that PA-MSHA improves the functions of CIK cells and shed new light on developing more potent therapeutic approaches for malignancies.

Pseudomonas aeruginosa-mannose-sensitive hemagglutinin inhibits pancreatic cancer cell proliferation and induces apoptosis via the EGFR pathway and caspase signaling.

Pseudomonas aeruginosa-mannose-sensitive hemagglutinin (PA-MSHA) has demonstrated efficacy against several solid tumors. In this study, we found that PA-MSHA inhibited the proliferation of PANC-1 and SW1990 pancreatic cancer cells, but had no obvious effects on HPDE6-C7 normal human pancreatic duct epithelial cells. Electron microscopy revealed the presence of apoptotic bodies and intracellular vacuole formation in PA-MSHA-treated pancreatic cancer cells. Flow cytometric analysis indicated the rate of apoptosis correlated with the PA-MSHA concentration. We observed a decrease in cell fractions in G0/G1 and G2/M phases, and an increase in the fraction in S phase (p < 0.01). PA-MSHA thus caused cell cycle arrest. Increasing concentrations of PA-MSHA did not alter total levels of EGFR, AKT or ERK, but levels of the corresponding phosphoproteins decreased. PA-MSHA also reduced tumor volume in a xenograft mouse model of pancreatic cancer (p < 0.01). Furthermore, caspase-3 levels decreased while the levels of cleaved caspase-3 increased (p < 0.01). These data suggest that by blocking cell cycle progression, PA-MSHA induces apoptosis and inhibits tumor growth. PA-MSHA-mediated inhibition of EGFR signaling and activation of the caspase pathway may play an important role in the induction of apoptosis in pancreatic cancer cells.

PA-MSHA inhibits proliferation and induces apoptosis in human non-small cell lung cancer cell lines with different genotypes.

The present study examined the potential of Pseudomonasaeruginosa-mannose sensitive hemagglutinin (PA-MSHA) to inhibit proliferation and induce apoptosis in non‑small‑cell lung cancer (NSCLC) cell lines. It also investigated its mechanisms of action in different genotypes of human NSCLC. A total of three NSCLC cell lines, PC‑9, A549, and NCI‑H1975, were treated with PA‑MSHA at different concentrations. The anti‑proliferative effect of PA‑MSHA was evaluated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell cycle distribution and apoptosis induced by the treatment were measured by flow cytometry (FCM) with AnnexinV/propidium iodide staining. Western blotting was conducted to determine the expression level of apoptosis‑associated proteins. PA‑MSHA was demonstrated to exert a time‑ and concentration‑dependent cytotoxic effect in PC‑9, A549, and NCI‑H1975 cells. The FCM indicated that all the different concentrations of PA‑MSHA used in the present study induce apoptosis and cell cycle arrest of NSCLC cells. Treatment with PA‑MSHA may exert anti‑proliferative effects on NSCLC cells by affecting regulation of the cell cycle and inducing apoptosis that is mediated in part by an intrinsic apoptosis signaling pathway. These data suggest that PA‑MSHA has the potential to inhibit proliferation and induce apoptosis in NSCLC cells. Furthermore, these data provide mechanistic details for the potential application of PA‑MSHA‑based therapeutic strategies for the treatment of different NSCLC genotypes. This present study suggests potential novel strategies to maximize effective therapeutic strategies targeting anti‑epidermal growth factor receptor for future clinical trials.

PA-MSHA inhibits the growth of doxorubicin-resistant MCF-7/ADR human breast cancer cells by downregulating Nrf2/p62.

Acquired resistance to doxorubicin in breast cancer is a serious therapeutic problem. In this study, we investigated whether Pseudomonas aeruginosa mannose‐sensitive hemagglutinin (PA‐MSHA) could inhibit the growth of doxorubicin‐resistant breast cancer cells. We found that the expressions of Nrf2 and p62 in breast cancer were higher than that in the corresponding adjacent normal tissues and benign breast epithelial cell. The expressions of Nrf2 and p62 in breast cancer doxorubicin‐resistant cells MCF‐7/ADR were higher than that in doxorubicin‐sensitive cells MCF‐7. Silencing of Nrf2 or p62 rendered breast cancer cells more susceptible to doxorubicin. We further demonstrated that PA‐MSHA inhibited growth and induced apoptosis of MCF‐7/ADR cells but not MCF‐7 cells. Subcutaneous administration of PA‐MSHA greatly inhibited the growth of xenograft tumors from MCF‐7/ADR cells in nude mice. In addition, PA‐MSHA could downregulate Nrf2 and p62 in vitro and in vivo. These results suggested that activation of Nrf2 and p62 was associated with doxorubicin resistance in breast cancer. PA‐MSHA could inhibit the growth of doxorubicin‐resistant MCF‐7/ADR cells and its potential mechanism might be due to the suppression of Nrf2/p62. It indicated the possibility of using PA‐MSHA in doxorubicin‐resistant breast cancer.

PA-MSHA in combination with EGFR tyrosine kinase inhibitor: A new strategy to overcome the drug resistance of non-small cell lung cancer cells

The inhibition of epidermal growth factor receptor (EGFR) signaling by Gefitinib provides a promising treatment strategy for non-small cell lung cancer (NSCLC); however, drug resistance to Gefitinib and other tyrosine kinase inhibitors presents a major issue. Using NSCLC cell lines with differential EGFR status, we examined the potency of PA-MSHA (Pseudomonas aeruginosa-mannose-sensitive hemagglutinin) in combination with Gefitinib on proliferation, apoptosis, cell cycle arrest, EGFR signaling and tumor growth. PC-9, A549, and NCI-H1975 cells were treated with PA-MSHA, Gefetinib, or PA-MSHA plus Gefetinib at different concentrations and times. The effects of the drugs on proliferation, cell cycle distribution and apoptosis were evaluated. The activation of EGFR and apoptotic signaling-related molecules was evaluated by Western blotting in the presence or absence of EGFR siRNA. Tumor growth and pathway signaling activation was assessed by xenografts in nude mice. A time-dependent and concentration-dependent cytotoxic effect of PA-MSHA was observed in all NSCLC cells tested. The combination of PA-MSHA plus Gefitinib enhanced the growth inhibition, sub-G1 content and apoptosis over that observed with either agent alone. Furthermore, the combination of PA-MSHA plus Gefitinib resulted in caspase-3/caspase-9 cleavage and increased inhibition of EGFR-dependent activation of AKT and ERK phosphorylation. Combination treatment was more effective in reducing tumor size and EGFR activation than either agent alone. These data suggest that PA-MSHA and Gefitinib function additively to suppress the proliferative effects of NSCLC cells of differential EGFR status. The combination of PA-MSHA and Gefitinib provides a potential new strategy to conquer drug resistance for anti-EGFR-targeted therapy of NSCLC.

Pseudomonas aeruginosa mannose-sensitive hemagglutinin inhibits proliferation and invasion via the PTEN/AKT pathway in HeLa cells.

We investigated the effects of Pseudomonas aeruginosa mannose-sensitive hemagglutinin (PA-MSHA) on the proliferation and invasion of human cervical cancer cell lines, as well as the molecular pathways underlying these effects. MTT cell proliferation assays revealed a time- and concentration-dependent cytotoxic effect of PA-MSHA on HeLa cells but not H8 cells. Flow cytometry with propidium iodide and annexin-V-fluorescein isothiocyanate labeling (FITC) indicated that various concentrations of PA-MSHA could induce apoptosis and G2-M cell cycle arrest in HeLa cells. PA-MSHA also impaired the migration and invasion abilities of HeLa cells in Wound healing and Transwell invasion assays. Western blot results demonstrated that PA-MSHA reduced the expression of p-AKT, p-GSK3β, BCL-2, Vimentin and β-catenin, but increased the levels of PTEN, BAD, BAX and E-cadherin in HeLa cells. Importantly, PTEN siRNA induced the activity of p-AKT, while PA-MSHA partly inhibited this induction, indicating that PA-MSHA may reduce the cell proliferation and invasion potential by activating PTEN and thus inhibiting the AKT pathway in vitro. These data suggest the potential application of PA-MSHA to the treatment of human cervical cancer.

Phase II study of pseudomonas aeruginosa-mannose-sensitive hemagglutinin in combination with capecitabine for HER2-negative metastatic breast cancer pretreated with anthracycline and taxane.

1053 Background: Metastatic breast cancer (MBC) remains an incurable disease despite major therapeutic advances. Pseudomonas aeruginosa–mannose-sensitive hemagglutinin (PA-MSHA) has been establishe...

Pseudomonas aeruginosa Mannose-Sensitive Hemagglutinin Promotes T-Cell Response via Toll-Like Receptor 4–Mediated Dendritic Cells to Slow Tumor Progression in Mice

Pseudomonas aeruginosa-mannose-sensitive hemagglutinin (PA-MSHA) as a drug may kill tumor cells and has been used clinically. However, the antitumor immune response of PA-MSHA is not completely understood. In this study, we found that treating Lewis lung carcinoma (3LL)-bearing mice with PA-MSHA plus 3LL antigen led to slower tumor progression and longer survival. After PA-MSHA treatment, T-cell number and dendritic cell maturation were both increased significantly at the tumor site. In addition, PA-MSHA in vitro stimulation resulted in the maturation of bone marrow-derived dendritic cells (BMDCs) from naive mice, showing higher costimulatory molecule expression, more cytokine secretion, lower endocytic activity, and stronger capacity to enhance T-cell activation. Toll-like receptor (TLR)4 but not TLR2 was required in the maturation process. More importantly, PA-MSHA-induced DCs were essential for PA-MSHA to enhance activation, expansion, and interferon (IFN)-γ secretion of TLR4-mediated T cells, which play a role in the antitumor effect of PA-MSHA. Thus, this study reveals PA-MSHA as a novel TLR4 agonist that elicits antitumor immune response to slow tumor progression.

Anti-proliferative effect of pseudomonas aeruginosa-manno sesensitive hemagglutinin on T24 and 5637 bladder cancer cell line

Objective To investigate the effects of pseudomonas aeruginosa-manno sesensitive hemagglutinin (PA-MSHA) on bladder cancer cells and the mechanism.Methods Cell counting kit-8 (CCK-8) assay was used to measure proliferation of tumor cells.The morphologic changes of apoptotic cells were observed by using immunofluorescence staining.Spectrophotometry was used for detection of Caspase-2 and Caspase-9.Results A450 values on T24 and 5637 cells treated with phosphate buffered saline were 1.31 and 1.62,respectively,and those were 0.28 and 0.41 in PA-MSHA group.As compared with cells treated with phosphate buffer (PBS),5637 or T24 cells treated with PA-MSHA for 24 h exhibited much less cytoplasmic organelles.PA-MSHA could induce activation of Caspase-3 and Caspase-9 in T24 cells and 5637 cells.Conclusion PA-MSHA can inhibit proliferation of T24 and 5637 cells,and induce apoptosis. Key words: Pseudomonas aeruginosa-manno sesensitive hemagglutinin; Bladder carcinoma; Apoptosis; Caspase-9