The Eph and Ephrin proteins, which constitute the largest family of receptor tyrosine kinases, are involved in normal tissue development and cancer progression. Here, we examined the expression and ...role of the B-type Eph receptor EphB2 in breast cancers. By immunohistochemistry using a progression tissue microarray of human clinical samples, we found EphB2 to be expressed in benign tissues, but strongly increased in cancers particularly in invasive and metastatic carcinomas. Subsequently, we found evidence that EphB2, whose expression varies in established cell breast lines, possesses multiple functions. First, the use of a DOX-inducible system to restore EphB2 function to low expressers resulted in decreased tumor growth in vitro and in vivo, while its siRNA-mediated silencing in high expressers increased growth. This function involves the onset of apoptotic death paralleled by caspases 3 and 9 activation. Second, EphB2 was also found to induce autophagy, as assessed by immunofluorescence and/or immunoblotting examination of the LC3, ATG5 and ATG12 markers. Third, EphB2 also has a pro-invasive function in breast cancer cells that involves the regulation of MMP2 and MMP9 metalloproteases and can be blocked by treatment with respective neutralizing antibodies. Furthermore, EphB2-induced invasion is kinase-dependent and is impeded in cells expressing a kinase-dead mutant EphB2. In summary, we identified a mechanism involving a triple role for EphB2 in breast cancer progression, whereby it regulates apoptosis, autophagy, and invasion.
•EphB2 is strongly increased in breast cancers, particularly in invasive carcinomas.•We show that EphB2 expression suppresses tumor growth, both in vitro and in vivo.•EphB2 regulates multiple functions: apoptosis, autophagy and invasion.•Invasive function involves MMP2 and MMP9, could blocked by neutralizing antibodies.•We show that EphB2-induced invasion is kinase-dependent.
A popular polyherbal formulation prepared from five plants (PHF5) may have anticancer effects. However, there is a lack of adequate scientific evidence. We assessed the anticancer, antioxidant, and ...acute toxicity effects of PHF5. Cancer cells were treated with 0 to 300 μg/mL PHF5 extract. Established assays were used to assess cytotoxicity, apoptosis, and radical scavenging activities. In the acute toxicity study, mice were administered a single oral dose (2,000 mg/kg) of PHF5, and biochemical and histopathological parameters were assessed. The IC
values of PHF5 on LoVo, HepG2, MCF-7, and MDA-MB 231 cells were 71.8, 64.8, 45.3, and 47.3 μg/mL, respectively. Fluorescence staining demonstrated that PHF5 induced MCF-7 cell apoptosis. After 48 h, the percentage of late apoptotic cells increased significantly compared with the control cells (74.16 ± 0.64 vs 3.7 ± 2.05,
< 0.05). No mortality or behavioral alterations were observed in mice treated with a single dose (2,000 mg/kg) of PHF5, indicating that the LD
value exceeded 2,000 mg/kg. However, histopathological changes were observed in the liver tissues. PHF5 has potential as a therapeutic agent for the treatment of human carcinoma. Further safety data will be necessary before clinical use.
COVID-19 is diagnosed using RT-PCR assays of samples from nasal and oropharyngeal swabs. People with negative RT-PCR often presented with clinical manifestations of COVID-19. The data on such ...patients are lacking. The present study aims to characterize the patients who were suspected COVID-19 cases and tested negative in RT-PCR compared to patients who had been tested RT-PCR positive.
This is a retrospective, observational study of adult suspected and confirmed patients of COVID-19 admitted to King Saud University Medical City, Riyadh, Saudi Arabia, from 1st March 2020 until 30th November 2020. Laboratory confirmation is done through nasal/pharyngeal swab specimens, tested positive in RT-PCR assay. Patients with initial negative RT-PCR test results were assessed again within 48−72 h to avoid false-negative results. Patient data were extracted from the electronic medical files of each included patient using a predesigned case report form.
The study included 488 (80.93%) patients with RT-PCR swab results positive, and 115 (19.07%) patients who were negative. Respiratory rate and diastolic blood pressure were higher among the swab-positive cases. More number of swab-negative patients had comorbidities such as coronary heart disease, chronic kidney disease, and carcinoma. Fever, cough, and shortness of breath were reported higher among the swab-positive cases. ALT and AST, and LDH levels were found higher among RT-PCR-positive patients. Serum creatinine, blood urea nitrogen and troponin were more elevated in RT-PCR-negative patients. Antibiotics, anticoagulants, and corticosteroids were used more by swab-positive patients. Significantly higher number of RT-PCR-positive patients required proning, high-flow nasal cannula, non-invasive mechanical ventilation, and invasive mechanical ventilation. Acute cardiac ischemia and death were found to be similar among the patients. However, deaths occurred significantly earlier among the swab-positive cases when compared to the swab-negative group.
Distinctive symptoms and markers of COVID-19 are more frequent among patients who had RT-PCR-positive results.
Studies have demonstrated that total osteocalcin (TOC) is associated with metabolic syndrome (MetS) and therefore might influence the risk of cardiovascular disease in humans. Undercarboxylated ...osteocalcin (uOC) regulates insulin secretion and sensitivity in mice, but its relation to MetS in humans is unclear. We aimed to determine whether uOC is related to MetS and/or its individual components and other cardiovascular risk factors in patients with type 2 diabetes mellitus (T2DM), and whether TOC and uOC have utility in predicting the cardiovascular risk. We studied 203 T2DM patients with and without MetS. MetS was defined based on the NCEP-ATP III criteria. A correlation analysis was performed between the three outcome variables: (i) TOC, (ii) uOC, and (iii) carboxylated osteocalcin (cOC) and MetS components and other cardiovascular risk factors. Both TOC and uOC were significantly lower in patients with MetS compared to those without MetS, independent of body mass index. In patients with MetS, uOC was significantly and positively correlated with HDL cholesterol, while TOC was significantly and negatively correlated with serum triglycerides. We report for the first time that uOC is related to lipid indices in patients with T2DM. Further studies are necessary to determine whether uOC can be utilized for cardiovascular risk assessments in these patients.
Studies have suggested that osteocalcin, a bone formation marker, is related to body metabolism and insulin sensitivity. Whether this relation is mediated through an interaction with adipokines ...remains unclear. The aim of this study was to assess the effect of weight loss on serum osteocalcin and its relation with three adipokines, adiponectin, chemerin, and resistin. Forty-nine obese nondiabetic males completed a four-month dietary program. Body mass index (BMI) decreased significantly from 39.7±7.6 to 37.8±7.6 (P<0.001). This was associated with significant reduction in waist circumference, fasting blood glucose, HOMA-IR, total and LDL-cholesterol, bone-specific alkaline phosphatase (BAP), and resistin (P<0.05). There was significant increase in serum adiponectin and undercarboxylated osteocalcin (uOC) (P<0.001). The changes in uOC levels were negatively correlated with changes in serum triglycerides (r=-0.51, P<0.001) and positively correlated with changes in BAP (r=0.52, P<0.001). In contrast, the changes in uOC were not correlated with changes in BMI, waist circumference, fasting blood glucose, HOMA-IR, total and LDL-cholesterol, hsCRP, vitamin D, and circulating adipokines. We concluded that the increase in serum uOC following weight loss is not related to the changes in circulating adipokines levels.
The ErbB-2 receptor is overexpressed in roughly 30% of human breast cancers. Moreover, approximately 50% of breast cancers are positive for high-risk human papillomaviruses (HPVs), specifically types ...16 and 18. Recently, we reported that ErbB-2 cooperates with E6/E7 oncoproteins of HPV type 16 to induce neoplastic transformation of human normal oral epithelial cells. We also demonstrated that E6/E7 of HPV type 16 converts non-invasive breast cancer cells to an invasive form. In order to investigate the effect of ErbB-2/E6/E7 cooperation in breast carcinogenesis, we generated double transgenic mice carrying ErbB-2 and E6/E7 of HPV type 16 under mouse mammary tumor virus (MMTV) and human keratin 14 promoters, respectively. Within six months, these double transgenic mice developed large and extensive invasive breast cancer in comparison to ErbB-2 or E6/E7 singly transgenic mice. Histological analysis of ErbB-2/E6/E7 transgenic mice tumors showed the presence of invasive breast carcinomas. However, the breast tissues from ErbB-2 and E6/E7 transgenic mice showed only in-situ cancer and normal mammary phenotype, respectively. In parallel, we examined the cooperation effect of ErbB-2 and E6/E7 in the human breast cancer cell line, BT20; in comparison to ErbB-2 and E6/E7 alone as well as wild type cells, we found that ErbB 2/E6/E7 together stimulate colony formation and cell migration in the BT20 cell line. Furthermore, we found that β-catenin is constitutively phosphorylated by c-Src and consequently trans-located to the nucleus in ErbB-2/E6/E7-breast cancer cells. These findings provide evidence that the ErbB-2 receptor cooperates with high-risk HPVs in breast tumorigenesis via β-catenin activation.
Inhibition of deregulated protein tyrosine kinases represents an attractive strategy for controlling cancer growth. However, target specificity is an essential aim of this strategy. In this report, ...pp60(c-Src) kinase and beta-catenin were found physically associated and constitutively activated on tyrosine residues in human colorectal cancer cells. The use of specific small-interfering RNAs (siRNA) validated pp60(c-Src) as the major kinase responsible for beta-catenin tyrosine phosphorylation in colorectal cancer. Src-dependent activation of beta-catenin was prevented by SKI-606, a novel Src family kinase inhibitor, which also abrogated beta-catenin nuclear function by impairing its binding to the TCF4 transcription factor and its trans-activating ability in colorectal cancer cells. These effects were seemingly specific, as cyclin D1, a crucial beta-catenin/TCF4 target gene, was also down-regulated by SKI-606 in a dose-dependent manner accounting, at least in part, for the reduced growth (IC50, 1.5-2.4 micromol/L) and clonogenic potential of colorectal cancer cells. Protein levels of beta-catenin remained substantially unchanged by SKI-606, which promoted instead a cytosolic/membranous retention of beta-catenin as judged by immunoblotting analysis of cytosolic/nuclear extracts and cell immunofluorescence staining. The SKI-606-mediated relocalization of beta-catenin increased its binding affinity to E-cadherin and adhesion of colorectal cancer cells, with ensuing reduced motility in a wound healing assay. Interestingly, the siRNA-driven knockdown of beta-catenin removed the effect of SKI-606 on cell-to-cell adhesion, which was associated with prolonged stability of E-cadherin protein in a pulse-chase experiment. Thus, our results show that SKI-606 operates a switch between the transcriptional and adhesive function of beta-catenin by inhibiting its pp60(c-Src)-dependent tyrosine phosphorylation; this could constitute a new therapeutic target in colorectal cancer.
EHD3 Eps15 homology (EH) domain-containing protein 3 is a protein that resides in tubular and vesicular membrane structures and participates in endocytic recycling, although all its functions are ...unknown. Since Ehd3 is most abundantly expressed in brain tissues, we examined its role in brain cancer progression. Using immunohistochemistry, we report loss of EHD3 expression in gliomas, including low-grade astrocytomas, suggesting that this is an early event in gliomagenesis. EHD3 expression is also very low in most of glioma cell lines tested. In two cell lines, a bisulfite sequencing method identifies promoter hypermethylation as a mechanism of Ehd3 silencing, and its expression was restored by the demethylating agent 5-Azacytidine. Doxycycline-inducible restoration of EHD3 expression to glioma cells decreases their growth and invasiveness and induces cell cycle arrest and apoptosis. Furthermore, shRNA-mediated Ehd3 silencing increases cell growth. Using a xenograft model, we demonstrate Ehd3 growth inhibitory functions in glioma cells in vivo. We suggest that Ehd3 functions as a tumor suppressor gene and loss of its expression is a very common event in gliomas. This is the first study to highlight the importance of a member of the C-terminal EHD proteins in cancer and to link their functions to the cell cycle and apoptosis.
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