Type I Angiotensin II Receptor Blockade Reduces Uremia-Induced Deterioration of Bone Material Properties

Chronic kidney disease (CKD) is associated with a high incidence of fractures. However, the pathophysiology of this disease is not fully understood, and limited therapeutic interventions are available. This study aimed to determine the impact of type 1 angiotensin II receptor blockade (AT-1RB) on preventing CKD-related fragility fractures and elucidate its pharmacological mechanisms. AT-1RB use was associated with a lower risk of hospitalization due to fractures in 3276 patients undergoing maintenance hemodialysis. In nephrectomized rats, administration of olmesartan suppressed osteocyte apoptosis, skeletal pentosidine accumulation, and apatite disorientation, and partially inhibited the progression of the bone elastic mechanical properties, while the bone mass was unchanged. Olmesartan suppressed angiotensin II-dependent oxidation stress and apoptosis in primary cultured osteocytes in vitro. In conclusion, angiotensin II-dependent intraskeletal oxidation stress deteriorated the bone elastic mechanical properties by promoting osteocyte apoptosis and pentosidine accumulation. Thus, AT-1RB contributes to the underlying pathogenesis of abnormal bone quality in the setting of CKD, possibly by oxidative stress. © 2020 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).Wakamatsu T., Iwasaki Y., Yamamoto S., et al. Type I Angiotensin II Receptor Blockade Reduces Uremia-Induced Deterioration of Bone Material Properties. Journal of Bone and Mineral Research, 36, 1, 67. https://doi.org/10.1002/jbmr.4159

Crucial role of carbonic anhydrase IX in tumorigenicity of xenotransplanted adult T-cell leukemia-derived cells

Carbonic anhydrase IX (CA9) is a membrane-associated carbonic anhydrase that regulates cellular pH, is upregulated in various solid tumors, and is considered to be a therapeutic target. Here, we describe the essential role of CA9 in the tumorigenicity of cells derived from human adult T-cell leukemia/lymphoma (ATL). We previously established the highly tumorigenic ST1-N6 subline from the ATL-derived ST1 cell line by serial xenotransplantation in NOG mice. In the present study, we first show that CA9 expression is strongly enhanced in ST1-N6 cells. We then sorted ST1 cells by high or low CA9 expression and established ST1-CA9(high) and ST1-CA9(low) sublines. ST1-CA9(high) cells, like ST1-N6 cells, were more strongly tumorigenic than ST1-CA9(low) or parental ST1 cells when injected into NOG mice. Knockdown of CA9 with shRNAs suppressed the ability of ST1-CA9(high) cells to initiate tumors, and the tumorigenicity of ST1 cells was significantly enhanced by introducing wild-type CA9 or a CA9 mutant with deletion of an intracytoplasmic domain. However, a CA9 with point mutations in the catalytic site did not increase the tumorigenicity of ST1 cells. Furthermore, we detected a small population of CA9(+)CD25(+) cells in lymph nodes of ATL patients. These findings suggest that CA9, and particularly its carbonic anhydrase activity, promotes the tumorigenicity of ATL-derived cells and may be involved in malignant development of lymphoma-type ATL

SERPINI1 regulates epithelial-mesenchymal transition in an orthotopic implantation model of colorectal cancer

An increasingly accepted concept is that the progression of colorectal cancer is accompanied by epithelial-mesenchymal transition (EMT). In our study, in order to characterize the properties of EMT in 16 colorectal cancer cell lines, the cells were first orthotopically implanted into nude mice, and the tumors in vivo, as well as cells cultured in vitro, were immunostained for EMT markers. The immunostaining revealed that seven of the cells had an epithelial phenotype with a high expression of E-cadherin, whereas other cells showed opposite patterns, such as a high expression of vimentin (CX-1, COLO205, CloneA, HCT116, and SW48). Among the cells expressing vimentin, some expressed vimentin in the orthotopic tumors but not in the cultured cells (SW480, SW620, and COLO320). We evaluated these findings in combination with microarray analyses, and selected five genes: CHST11, SERPINI1, AGR2, FBP1, and FOXA1. Next, we downregulated the expression of SERPINI1 with siRNA in the cells, the results of which showed reverse-EMT changes at the protein level and in the cellular morphology. Along with immunohistochemical analyses, we confirmed the effect of the intracellular and secreted SERPINI1 protein of SW620 cells, which supported the importance of SERPINI1 in EMT. The development of therapeutic strategies targeting EMT is ongoing, including methods targeting the transforming growth factor-β signaling pathway as well as the Wnt pathway. SERPINI1 is an important regulator of EMT. Our findings help to elucidate the signaling pathways of EMT, hopefully clarifying therapeutic pathways as well

CD271 Defines a Stem Cell-Like Population in Hypopharyngeal Cancer

<div><p>Cancer stem cells contribute to the malignant phenotypes of a variety of cancers, but markers to identify human hypopharyngeal cancer (HPC) stem cells remain poorly understood. Here, we report that the CD271⁺ population sorted from xenotransplanted HPCs possesses an enhanced tumor-initiating capability in immunodeficient mice. Tumors generated from the CD271⁺ cells contained both CD271⁺ and CD271⁻ cells, indicating that the population could undergo differentiation. Immunohistological analyses of the tumors revealed that the CD271⁺ cells localized to a perivascular niche near CD34⁺ vasculature, to invasive fronts, and to the basal layer. In accordance with these characteristics, a stemness marker, <i>Nanog</i>, and <i>matrix metalloproteinases (MMPs)</i>, which are implicated in cancer invasion, were significantly up-regulated in the CD271⁺ compared to the CD271<b>⁻</b> cell population. Furthermore, using primary HPC specimens, we demonstrated that high CD271 expression was correlated with a poor prognosis for patients. Taken together, our findings indicate that CD271 is a novel marker for HPC stem-like cells and for HPC prognosis.</p></div