In a published case-control study (GSE152075) from SARS-CoV-2 positive (n=403) and negative patients (n=50), we analyzed the response to infection assessing gene expression of host cell receptors and antiviral proteins. The expression analysis associated with reported risk factors for COVID-19 was also assessed. SARS-CoV-2 cases had higher ACE2 , but lower TMPRSS2, BSG/CD147 and CTSB expression compared with negative cases. COVID-19 patients’ age negatively affected ACE2 expression. MX1 and MX2 were higher in COVID-19 patients. A negative trend for MX1 and MX2 was observed as patients’ age increased. Principal Component Analysis determined that ACE2 , MX1 , MX2, and BSG/CD147 expression was able to cluster non-COVID-19 and COVID-19 individuals. Multivariable regression showed that MX1 expression significantly increased for each unit of viral load increment. Altogether, these findings support differences in ACE2 , MX1 , MX2, and BSG/CD147 expression between COVID-19 and non-COVID-19 patients and point out to MX1 as a critical responder in SARS-CoV-2 infection.

Background: Prostate cancer (PCa) dissemination shows a tendency to develop in the bone, where heme oxygenase 1 (HO-1) plays a critical role in bone remodeling. Previously by LC/ESI-MSMS, we screened for HO-1 interacting proteins and identified annexin 2 (ANXA2). The aim of this study was to analyze the relevance of ANXA2/HO-1 in PCa and bone metastasis. Methods: We assessed ANXA2 levels using a co-culture transwell system of PC3 cells (pre-treated or not with hemin, an HO-1 specific inducer) and the pre-osteoclastic Raw264.7 cell line. Results: Under co-culture conditions, ANXA2 mRNA levels were significantly modulated in both cell lines. Immunofluorescence analysis unveiled a clear ANXA2 reduction in cell membrane immunostaining for Raw264.7 under the same conditions. This effect was supported by the detection of a decrease in Ca 2+ concentration in the conditioned medium. HO-1 induction in tumor cells prevented both, the ANXA2 intracellular relocation and the decrease in Ca 2+ concentration. Further, secretome analysis revealed urokinase (uPA) as a key player in the communication between osteoclast progenitors and PC3 cells. To assess the clinical significance of ANXA2/HO-1, we performed a bioinformatics analysis and identified that low expression of each gene strongly associated with poor prognosis in PCa regardless of the clinico-pathological parameters assessed. Further, these genes appear to behave in a dependent manner. Conclusions: ANXA2/HO-1 rises as a critical axis in PCa.Biomolecules 2020, 10, 467 2 of 24 microenvironment communicate and interact with each other to develop a fertile niche for the promotion of the metastatic process [3][4][5].Evidence has recognized inflammation as a risk factor for this neoplastic disease [6]. Heme oxygenase 1 (HO-1), encoded by the HMOX1 gene, is a stress response protein and a critical mediator of cellular homeostasis [7]. Although the role of HO-1 in cancer is controversial [8,9], we have shown that its pharmacologic or genetic upregulation is associated with a less aggressive phenotype in PCa [10]. HO-1 impairs tumor growth and angiogenesis in vivo and downregulates the expression of target genes associated with inflammation in PCa [11,12]. In the metastatic bone site, we demonstrated that HO-1 is capable of modulating signaling pathways relevant to skeletal PCa metastasis, such as FoxO/β-catenin and promotes bone remodeling when human tumor cells are transplanted into the femur of SCID mice [13]. Moreover, we have shown the direct effect of HO-1 on bone turnover and remodeling. When assessing the physiological impact of Hmox1 gene knockout on bone metabolism in vivo, histomorphometric analysis of Hmox1−/− mice bones exhibited significantly decreased bone density. A positive correlation between Hmox1 expression and key bone markers was observed in primary mouse osteoblasts (PMOs) [14]. These observations highlight the importance of HO-1 expression in bone, not only for the physiology of bone cells but also in the modulation of the communication between PMOs and PC...