Mesenchymal Stem Cells Promote Tumor Progression via Inducing Stroma Remodeling on Rabbit VX2 Bladder Tumor Model

Chemotherapeutic Drugs Endow Gastric Cancer Mesenchymal Stem Cells with Stronger Tumor-Promoting Ability

Gastric cancer (GC) is one of the most aggressive tumors and has a poor prognosis. It has been demonstrated that gastric cancer mesenchymal stem cells (GC-MSCs) can promote the progression, metastasis, and chemoresistance of GC through various mechanisms, but the effect of GC-MSCs on GC during chemotherapy is still unknown. In this study, flow cytometry, CCK8 assay, migration assay, colony formation assay, and western blot were conducted. We also analyzed GC patients from the cancer genome atlas (TCGA). Our results showed that GC-MSCs were resistant to 5-FU and Taxol at the IC50 concentration for GC cells, and 5-FU could promote the migration of GC-MSCs at low doses. Furthermore, the conditioned medium of GC-MSCs pretreated with chemotherapeutic drugs was more effective in promoting the proliferation, migration, and stemness of GC cell lines than the conditioned medium of GC-MSCs without chemotherapeutic drugs treatment. These effects were dependent on the activation of phosphorylated AKT (p-AKT) in GC cell lines. Correspondingly, the inhibition of p-AKT reversed the tumor-promoting effect of the conditioned medium of GC-MSCs pretreated with chemotherapeutic drugs. Additionally, the expression of AKT1 was higher in GC tissues than in both paracancerous tissues and normal tissues, and patients resistant to chemotherapy expressed more AKT1 compared to those who were sensitive. Taken together, our data demonstrated that GC-MSCs gained more tumor-promoting abilities during chemotherapy.

The Bladder Tumor Microenvironment Components That Modulate the Tumor and Impact Therapy

The tumor microenvironment (TME) is complex and involves many different cell types that seemingly work together in helping cancer cells evade immune monitoring and survive therapy. The advent of single-cell sequencing has greatly increased our knowledge of the cell types present in the tumor microenvironment and their role in the developing cancer. This, coupled with clinical data showing that cancer development and the response to therapy may be influenced by drugs that indirectly influence the tumor environment, highlights the need to better understand how the cells present in the TME work together. This review looks at the different cell types (cancer cells, cancer stem cells, endothelial cells, pericytes, adipose cells, cancer-associated fibroblasts, and neuronal cells) in the bladder tumor microenvironment. Their impact on immune activation and on shaping the microenvironment are discussed as well as the effects of hypertensive drugs and anesthetics on bladder cancer.

Rabbit VX2 Liver Tumor Model: A Review of Clinical, Biology, Histology, and Tumor Microenvironment Characteristics

The rabbit VX2 is a large animal model of cancer used for decades by interventional radiologists to demonstrate the efficacy of various locoregional treatments against liver tumors. What do we know about this tumor in the new era of targeted therapy and immune-oncology? The present paper describes the current knowledge on the clinics, biology, histopathology, and tumor microenvironment of VX2 based on a literature review of 741 publications in the liver and in other organs. It reveals the resemblance with human cancer (anatomy, vascularity, angiogenic profile, drug sensitivity, immune microenvironment), the differences (etiology, growth rate, histology), and the questions still poorly explored (serum and tissue biomarkers, genomic alterations, immune checkpoint inhibitors efficacy).

TGF-β and microRNA Interplay in Genitourinary Cancers

Genitourinary cancers (GCs) include a large group of different types of tumors localizing to the kidney, bladder, prostate, testis, and penis. Despite highly divergent molecular patterns, most GCs share commonly disturbed signaling pathways that involve the activity of TGF-β (transforming growth factor beta). TGF-β is a pleiotropic cytokine that regulates key cancer-related molecular and cellular processes, including proliferation, migration, invasion, apoptosis, and chemoresistance. The understanding of the mechanisms of TGF-β actions in cancer is hindered by the "TGF-β paradox" in which early stages of cancerogenic process are suppressed by TGF-β while advanced stages are stimulated by its activity. A growing body of evidence suggests that these paradoxical TGF-β actions could result from the interplay with microRNAs: Short, non-coding RNAs that regulate gene expression by binding to target transcripts and inducing mRNA degradation or inhibition of translation. Here, we discuss the current knowledge of TGF-β signaling in GCs. Importantly, TGF-β signaling and microRNA-mediated regulation of gene expression often act in complicated feedback circuits that involve other crucial regulators of cancer progression (e.g., androgen receptor). Furthermore, recently published in vitro and in vivo studies clearly indicate that the interplay between microRNAs and the TGF-β signaling pathway offers new potential treatment options for GC patients.

Mesenchymal Stem Cells Accelerate the Remodeling of Bladder VX2 Tumor Interstitial Microenvironment by TGFβ1-Smad Pathway

Background: Mesenchymal stem cells (MSCs) have been proved to be able to differentiate into cells that are conducive to tumor growth and invasion. The mechanism is not clear. This present study was aimed to find out whether TGFβ1-Smad pathway was involved in this process. Methods: For the in vitro experiment, five groups of MSCs were cultured to test whether VX2 culture supernatant could induce the differentiation of MSCs into myofibroblasts. And then transforming growth factor β1(TGFβ1) receptor or Smad2 of MSCs were blocked by RNA interference technique to test whether TGFβ1-Smad pathway was involved in the differentiation. In the animal experiment, different kinds of MSCs were co-inoculated with VX2 cells in bladder to test whether the blockage of TGFβ1 receptor or Smad2 of MSCs could affect the expression of TGFβ1, epidermal growth factor (EGF), fibroblast activation protein alpha (FAPa), and matrix metalloprotein 9 (MMP9) in five animal groups. Results: VX2 culture supernatant could up-regulate the expression of α-SMA and Vimentin in MSCs, which indicated that VX2 culture supernatant could induce the differentiation of MSCs into myofibroblasts. Either the Blockage of TGFβ1 receptor or Smad2 of MSCs could lead to decreased expression of α-SMA and Vimentin in MSCs. In the animal experiment, MSCs could favor VX2 bladder tumor growth and up-regulate the expression of TGFβ1, EGF, FAPa, MMP9 in VX2 tumor tissue. However, when TGFβ1 receptor or Smad2 of MSCs was blocked, the above effects were attenuated. Conclusions: Under the induction of tumor microenvironment, MSCs can differentiate into myofibroblasts and then affect tumor interstitial microenvironment remodeling. This process is mediated by TGFβ1-Smad2 pathway.

IL22 furthers malignant transformation of rat mesenchymal stem cells, possibly in association with IL22RA1/STAT3 signaling

Mesenchymal stem cells (MSCs) hold great promise as potential therapies for tumors through the delivery of various anticancer agents. However, exogenous tissue‑derived MSCs, such as those of bone marrow, have exhibited a tendency for malignant transformation in the tumor microenvironment. This issue remains controversial and is poorly understood. In the present study, the role of interleukin 22 (IL22)/IL22 receptor subunit α 1 (IL22RA1) and signal transducer and activator of transcription 3 (STAT3) signaling in the malignant transformation of MSCs was investigated. Following isolation of rat MSCs and their indirect co‑culture with C6 glioma cells, the transformed MSCs exhibited tumor cell characteristics. The Cancer Genome Atlas‑Glioblastoma Multiforme analysis revealed that primary and recurrent glioblastomas have increased IL22RA1 expression, compared with normal tissues, whereas the expression of IL22 was low in glioblastoma and normal tissues. mRNA and protein expression levels of IL22RA1 were significantly increased in the MSCs co‑cultured with C6 glioma cells. Furthermore, MSCs incubated with IL22 exhibited increased proliferation, migration and invasion. STAT3 demonstrated activation and nuclear translocation in the presence of IL22. Additionally, STAT3 small interfering RNA significantly inhibited the migration and invasion ability of MSCs, and the expression of the STAT3 downstream targets cyclin D1 and B‑cell lymphoma‑extra large under IL22 stimulation, indicating that IL22 also promoted MSC migration and invasion through STAT3 signaling. These data indicated that IL22 serves a critical role in the malignant transformation of rat MSCs, which is associated with an enhancement of the IL22RA1/STAT3 signaling pathway in the tumor microenvironment.