MEK inhibition enhances efficacy of bacillus Calmette-Guérin on bladder cancer cells by reducing release of Toll-like receptor 2-activated antimicrobial peptides

Change in Tissue Microbiome and Related Human Beta Defensin Levels Induced by Antibiotic Use in Bladder Carcinoma

It is now generally accepted that the success of antitumor therapy can be impaired by concurrent antibiotic therapy, the presence of certain bacteria, and elevated defensin levels around the tumor tissue. The aim of our current investigation was to identify the underlying changes in microbiome and defensin levels in the tumor tissue induced by different antibiotics, as well as the duration of this modification. The microbiome of the tumor tissues was significantly different from that of healthy volunteers. Comparing only the tumor samples, no significant difference was confirmed between the untreated group and the group treated with antibiotics more than 3 months earlier. However, antibiotic treatment within 3 months of analysis resulted in a significantly modified microbiome composition. Irrespective of whether Fosfomycin, Fluoroquinolone or Beta-lactam treatment was used, the abundance of Bacteroides decreased, and Staphylococcus abundance increased. Large amounts of the genus Acinetobacter were observed in the Fluoroquinolone-treated group. Regardless of the antibiotic treatment, hBD1 expression of the tumor cells consistently doubled. The increase in hBD2 and hBD3 expression was the highest in the Beta-lactam treated group. Apparently, antibiotic treatment within 3 months of sample analysis induced microbiome changes and defensin expression levels, depending on the identity of the applied antibiotic.

MEK homologue is involved in immune response by regulating antimicrobial peptides expression in Chinese mitten crab Eriocheir sinensis

MEK activates the phosphorylation of downstream molecules involved in various immune responses. In this study, an MEK homologue gene in Chinese mitten crab Eriocheir sinensis (designated as EsMEK) was investigated. EsMEK mRNA was constitutively expressed in all tissues with higher expression in hepatopancreas, hemocytes, and gills. EsMEK protein was mainly localized in the cytoplasm. Lipopolysaccharide (LPS) and Aeromonas hydrophila challenge significantly increased the mRNA levels of EsMEK in hemocytes. In addition, the mRNA expression level of some antimicrobial peptides (AMPs), including EsWAP, EsDWD1, and EsALF decreased significantly due to the inhibition of EsMEK by specific dsRNA in LPS-challenged crabs. Downstream pathway analysis revealed that the phosphorylation of EsERK decreased prominently after EsMEK inhibition. These results suggested that EsMEK played an important role in regulating the expression of antimicrobial peptides in E. sinensis through MEK-ERK pathway.

Bladder Tissue Microbiome Composition in Patients of Bladder Cancer or Benign Prostatic Hyperplasia and Related Human Beta Defensin Levels

Balance between the microbiome associated with bladder mucosa and human beta defensin (HBD) levels in urine is a dynamic, sensitive and host-specific relationship. HBD1—possessing both antitumor and antibacterial activity—is produced constitutively, while the inducible production of antibacterial HBD2 and HBD3 is affected by bacteria. Elevated levels of HBD2 were shown to cause treatment failure in anticancer immunotherapy. Our aim was to assess the relationship between microbiome composition characteristic of tumor tissue, defensin expression and HBD levels measured in urine. Tissue samples for analyses were removed during transurethral resection from 55 bladder carcinoma and 12 prostatic hyperplasia patients. Microbiome analyses were carried out with 16S rRNS sequencing. Levels of HBD mRNA expression were measured with qPCR from the same samples, and urinary amounts of HBD1, 2 and 3 were detected with ELISA in these patients, in addition to 34 healthy volunteers. Mann–Whitney U test, Wilcoxon rank sum test (alpha diversity) and PERMANOVA analysis (beta diversity) were performed. Defensin-levels expressed in the tumor did not clearly determine the amount of defensin measurable in the urine. The antibacterial and antitumor defensin (HBD1) showed decreased levels in cancer patients, while others (HBD2 and 3) were considerably increased. Abundance of Staphylococcus, Corynebacterium and Oxyphotobacteria genera was significantly higher, the abundance of Faecalibacterium and Bacteroides genera were significantly lower in tumor samples compared to non-tumor samples. Bacteroides, Parabacteroides and Faecalibacterium abundance gradually decreased with the combined increase in HBD2 and HBD3. Higher Corynebacterium and Staphylococcus abundances were measured together with higher HBD2 and HBD3 urinary levels. Among other factors, defensins and microorganisms also affect the development, progression and treatment options for bladder cancer. To enhance the success of immunotherapies and to develop adjuvant antitumor therapies, it is important to gain insight into the interactions between defensins and the tumor-associated microbiome.

MEK is a promising target in the basal subtype of bladder cancer

While many resources exist for the drug screening of bladder cancer cell lines in 2D culture, it is widely recognized that screening in 3D culture is more representative of in vivo response. Importantly, signaling changes between 2D and 3D culture can result in changes to drug response. To address the need for 3D drug screening of bladder cancer cell lines, we screened 17 bladder cancer cell lines using a library of 652 investigational small-molecules and 3 clinically relevant drug combinations in 3D cell culture. Our goal was to identify compounds and classes of compounds with efficacy in bladder cancer. Utilizing established genomic and transcriptomic data for these bladder cancer cell lines, we correlated the genomic molecular parameters with drug response, to identify potentially novel groups of tumors that are vulnerable to specific drugs or classes of drugs. Importantly, we demonstrate that MEK inhibitors are a promising targeted therapy for the basal subtype of bladder cancer, and our data indicate that drug screening of 3D cultures provides an important resource for hypothesis generation.

Structure establishment of three-dimensional (3D) cell culture printing model for bladder cancer

Purpose

Two-dimensional (2D) cell culture is a valuable method for cell-based research but can provide unpredictable, misleading data about in vivo responses. In this study, we created a three-dimensional (3D) cell culture environment to mimic tumor characteristics and cell-cell interactions to better characterize the tumor formation response to chemotherapy.

Materials and methods

We fabricated the 3D cell culture samples using a 3D cell bio printer and the bladder cancer cell line 5637. T24 cells were used for 2D cell culture. Then, rapamycin and Bacillus Calmette-Guérin (BCG) were used to examine their cancer inhibition effects using the two bladder cancer cell lines. Cell-cell interaction was measured by measuring e-cadherin and n-cadherin secreted via the epithelial-mesenchymal transition (EMT).

Results

We constructed a 3D cell scaffold using gelatin methacryloyl (GelMA) and compared cell survival in 3D and 2D cell cultures. 3D cell cultures showed higher cancer cell proliferation rates than 2D cell cultures, and the 3D cell culture environment showed higher cell-to-cell interactions through the secretion of E-cadherin and N-cadherin. Assessment of the effects of drugs for bladder cancer such as rapamycin and BCG showed that the effect in the 2D cell culture environment was more exaggerated than that in the 3D cell culture environment.

Conclusions

We fabricated 3D scaffolds with bladder cancer cells using a 3D bio printer, and the 3D scaffolds were similar to bladder cancer tissue. This technique can be used to create a cancer cell-like environment for a drug screening platform.

Forkhead box M1 (FOXM1) transcription factor is a key oncogenic driver of aggressive human meningioma progression

AIMS

Aggressive meningioma remains incurable with neither chemo- nor targeted therapies proven effective, largely due to unidentified genetic alterations and/or aberrant oncogenic pathways driving the disease progression. In this study, we examined the expression and function of Forkhead box M1 (FOXM1) transcription factor during meningioma progression.

METHODS

Human meningioma samples (n = 101) were collected, followed by Western blotting, quantitative PCR, immunohistochemical and progression-free survival (PFS) analyses. For in vitro assays, FOXM1 was overexpressed or knocked-down in benign (SF4433 and SF4068) or malignant (SF3061 and IOMM-Lee) human meningioma cell lines respectively. For in vivo studies, siomycin A (a FOXM1 inhibitor)-pretreated or control IOMM-Lee cells were implanted subcutaneously in nude mice.

RESULTS

FOXM1 expression was increased in higher grades of meningioma and correlated with the mitotic index in the tumour tissue. Moreover, FOXM1 was increased in recurrent meningioma compared with the matched primary lesions. The patients who had higher FOXM1 expression had shorter PFS. In the subsequent in vitro assays, knockdown of FOXM1 in malignant meningioma cell lines resulted in decreased tumour cell proliferation, angiogenesis and invasion, potentially via regulation of β-catenin, cyclin D1, p21, interleukin-8, vascular endothelial growth factor-A, PLAU, and epithelial-to-mesenchymal transition-related genes, whereas overexpression of FOXM1 in benign meningioma cell lines had the opposite effects. Last, suppression of FOXM1 using a pharmacological inhibitor, siomycin A, decreased tumour growth in an in vivo mouse model.

CONCLUSIONS

Our data demonstrate that FOXM1 is a key transcription factor regulating oncogenic signalling pathways in meningioma progression, and a promising therapeutic target for aggressive meningioma.

Secalonic acid D induces cell apoptosis in both sensitive and ABCG2-overexpressing multidrug resistant cancer cells through upregulating c-Jun expression

Secalonic acid D (SAD) could inhibit cell growth in not only sensitive cells but also multidrug resistant (MDR) cells. However, the molecular mechanisms need to be elucidated. Here, we identified that SAD possessed potent cytotoxicity in 3 pairs of MDR and their parental sensitive cells including S1-MI-80 and S1, H460/MX20 and H460, MCF-7/ADR and MCF-7 cells. Furthermore, SAD induced cell G2/M phase arrest via the downregulation of cyclin B1 and the increase of CDC2 phosphorylation. Importantly, JNK pathway upregulated the expression of c-Jun in protein level and increased c-Jun phosphorylation induced by SAD, which was linked to cell apoptosis via c-Jun/Src/STAT3 pathway. To investigate the mechanisms of upregulation of c-Jun protein by SAD, the mRNA expression level and degradation of c-Jun were examined. We found that SAD did not alter the mRNA level of c-Jun but inhibited its proteasome-dependent degradation. Taken together, these results implicate that SAD induces cancer cell death through c-Jun/Src/STAT3 signaling axis by inhibiting the proteasome-dependent degradation of c-Jun in both sensitive cells and ATP-binding cassette transporter sub-family G member 2 (ABCG2)-mediated MDR cells.

Rapamycin enhances growth inhibition on urothelial carcinoma cells through LKB1 deficiency-mediated mitochondrial dysregulation

Rapamycin, a mammalian target of rapamycin (mTOR) inhibitor, has significant potential for application in the treatment of urothelial carcinoma (URCa) of the bladder. Previous studies have shown that regulation of the AMP-activated serine/threonine protein kinase (AMPK)-mTOR signaling pathway enhances apoptosis by inducing autophagy or mitophagy in bladder cancer. Alteration of liver kinase B1 (LKB1)-AMPK signaling leads to mitochondrial dysfunction and the accumulation of autophagy-related proteins as a result of mitophagy, resulting in enhanced cell sensitivity to drug treatments. Therefore, we hypothesized that LKB1 deficiency in URCa cells could lead to increased sensitivity to rapamycin by inducing mitochondrial defect-mediated mitophagy. To test this, we established stable LKBI-knockdown URCa cells and analyzed the effects of rapamycin on their growth. Rapamycin enhanced growth inhibition and apoptosis in stable LKB1-knockdown URCa cells and in a xenograft mouse model. In spite of the stable downregulation of LKB1 expression, rapamycin induced AMPK activation in URCa cells, causing loss of the mitochondrial membrane potential, ATP depletion, and ROS accumulation, indicating an alteration of mitochondrial biogenesis. Our findings suggest that the absence of LKB1 can be targeted to induce dysregulated mitochondrial biogenesis by rapamycin treatment in the design of novel therapeutic strategies for bladder cancer.

Dual targeting c-met and VEGFR2 in osteoblasts suppresses growth and osteolysis of prostate cancer bone metastasis

Prostate cancer characteristically induces osteoblastic bone metastasis, for which no therapies are available. A dual kinase inhibitor of c-Met and VEGFR-2 (cabozantinib) was shown to reduce prostate cancer growth in bone, with evidence for suppressing osteoblastic activity. However, c-Met and VEGFR2 signaling in osteoblasts in the context of bone metastasis remain unclear. Here we show using cultured osteoblasts that hepatocyte growth factor (HGF) and VEGF-A increased receptor activator of NFκB ligand (RANKL) and M-CSF, two essential factors for osteoclastogenesis. Insulin-like growth factor-1 (IGF1) also increased RANKL and M-CSF via c-Met transactivation. The conditioned media from IGF1-, HGF-, or VEGFA-treated osteoblasts promoted osteoclastogenesis that was reversed by inhibiting c-Met and/or VEGFR2 in osteoblasts. In vivo experiments used cabozantinib-resistant prostate cancer cells (PC-3 and C4-2B) to test the effects of c-Met/VEGFR2 inhibition specifically in osteoblasts. Cabozantinib (60 mg/kg, 3 weeks) suppressed tumor growth in bone and reduced expression of RANKL and M-CSF and subsequent tumor-induced osteolysis. Collectively, inhibition of c-Met and VEGFR2 in osteoblasts reduced RANKL and M-CSF expression, and associated with reduction of tumor-induced osteolysis, suggesting that c-Met and VEGFR2 are promising therapeutic targets in bone metastasis.