Differential effects of adipose tissue stromal cells on the apoptosis, growth and invasion of bladder urothelial carcinoma between the superficial and invasive types

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.

Bystander effects induced by the interaction between urothelial cancer cells and irradiated adipose tissue-derived stromal cells in urothelial carcinoma

Cell-cell interactions between cancer cells and neighboring adipose tissue-derived stromal cells (ATSCs) are known to regulate the aggressiveness of cancer cells. In addition, the radiation-induced bystander effect is an important modulator of cancer cell kinetics. Radiation therapy is often given for urinary cancer, but the biological effects of the irradiated cancer stroma, including adipose tissue, on urothelial carcinoma (UC) remain unclear. We investigated the bystander effect of irradiated ATSCs on UC using a collagen gel culture method to replicate irradiated ATSC-cancer cell interactions after a single 12-Gy dose of irradiation. Proliferative activity, invasive capacity, protein expression and nuclear translocation of p53 binding protein-1 (53BP1) were analyzed. Irradiated ATSCs significantly inhibited the growth and promoted the apoptosis of UC cells in comparison to non-irradiated controls. The invasiveness of UC cells was increased by irradiated ATSCs, but not irradiated fibroblasts. Nuclear translocation of 53BP1 protein due to the bystander effect was confirmed in the irradiated group. Irradiated ATSCs regulated the expressions of the insulin receptor, insulin-like growth factor-1 and extracellular signal-regulated kinase-1/2 in UC. In conclusion, the bystander effect of irradiated ATSCs is a critical regulator of UC, and the actions differed depending on the type of mesenchymal cell involved. Our alternative culture model is a promising tool for further investigations into radiation therapy for many types of cancer.

Progress in cell culture systems for pathological research

Cell culture is a well-established standard technique and a fundamental tool in biology and medicine. Establishment of a novel culture method by meeting various challenges can sometimes open up new fields of cell biology and medicine. An artificial microenvironment for cultured cells is made up of complicated factors, including cytokines, scaffold material type, cell-cell interactions, and physical stress. To replicate the tissue architecture, cell-cell interactions, and specific physical microenvironment, we previously demonstrated the effectiveness of a three-dimensional culture system, and further established two simple culture systems: air-liquid interface (ALI) and fluid flow stress (FFS). A three-dimensional collagen gel culture system can replicate cell-cell interactions in vitro. As skin is constantly exposed to air, the ALI system closely mimicked the skin microenvironment and maintained the homeostasis of the epidermis and dermis. The ALI culture system also revealed the possibility of skin regeneration through ectopic mesenchymal cell involvement. Fluid streaming and shear stress were recently demonstrated to constitute the critical microenvironment for various cell types. The FFS system demonstrated that fluid streaming induced epithelial-mesenchymal transition of mesothelial cells, leading to peritoneal fibrosis. Our novel culture systems will hopefully open up new fields of regenerative medicine and pathological research.