ABSTRACT
High-entropy alloys (HEAs) have great potential as accident-tolerant fuel (ATF) cladding. Aluminum-forming duplex (BCC and FCC) stainless-steel (ADSS) is a candidate for ATF cladding, but the multiphase composition is detrimental to its corrosion resistance. In this paper, two single-phase HEAs were prepared by adjusting the content of each element in the ADSS alloy. The two HEAs were designed as Al0.05(CrFeNi)0.95(FCC) and Al0.25(FeCrNi)0.75(BCC). Their corrosion behavior under simulated pressurized water reactor (PWR) primary water was investigated. The corrosion products and corrosion mechanisms of these two HEAs were explored. The results show that the corrosion resistance of HEA alloys containing FCC is better than that of BCC and ADSS alloys. At the same time, the reason why the BCC structure composed of these four elements is not resistant to corrosion is revealed.
ABSTRACT
Unconventional prefoldin RPB5 interactor (URI), a RNA polymerase II Subunit 5-Interacting protein, is known to participate in the regulation of nutrient-sensitive mTOR-dependent transcription programs. Multiple studies have recently demonstrated that URI functions as an oncoprotein, possibly through the mTOR pathway, and regulates tumor cell motility, invasion, and metastasis. However, whether and how URI plays a role in gastric oncogenesis has not been elucidated. Due to drug resistance, recurrence and metastasis, the prognosis of gastric cancer remains poor. This study aims to explore the effects of URI on gastric cancer cells by focusing on their migratory ability and resistance to adriamycin. URI was over-expressed or knocked-down in MGC-803 and HGC-27 gastric cancer cells using URI plasmid or siRNA transfection approach. The cell viability, apoptosis, and migration ability were then examined by the CCK-8 assay, flow cytometer Annexin V/PI staining, and the Transwell cell migration assay respectively. The protein levels of apoptosis and EMT related genes were detected by western blot. The results showed that overexpression of URI promoted while knock-down of URI inhibited gastric cancer cell proliferation. URI overexpression resulted in increased Bcl-2 expression but decreased levels of Bax, cleaved PARP-1 and cleaved caspase-3. Conversely, cells treated with URI siRNA showed increased adriamycin induced apoptosis, along with reduced Bcl-2, but increased Bax, cleaved PARP-1 and cleaved caspase-3 expression. We have also shown that overexpression of URI enhanced cancer cell proliferation and migration with higher levels of Snail and Vimentin, whereas knockdown of URI in MGC-803 and HGC-27 cells inhibited proliferation and migration with decreased Snail and Vimentin expression. Together, our results support that URI promotes cell survival and mobility and acts as a chemotherapeutics resistant protein in MGC-803 and HGC-27 cells. URI might be a potential biomarker for gastric cancer diagnostics and prognostics.
ABSTRACT
Chromium VI can provoke oxidative stress, DNA damage, cytotoxicity, mutagenesis and carcinogenesis. Aberrantly high level of reactive oxygen species (ROS) has been associated with oxidative stress and subsequent DNA damage. Notably, multiple previous studies have shown the increased level of ROS in chromium (VI) induced oxidative stress, but its effect on cell death and the underlying mechanism remain to be determined. In this study, we aimed to investigate the role of URI, an unconventional prefoldin RBP5 interactor, in potassium dichromate induced oxidative stress and cell death through in vitro loss-of-function studies. We have shown that knockdown of URI in human gastric cancer SGC-7901 cells by URI siRNA enhanced potassium dichromate-induced production of ROS. The level of rH2AX, a marker of DNA damage, was significantly increased, along with a reduced cell viability in URI siRNA treated cells that were also exposed to potassium dichromate. Comet assay showed that URI knockdown increased the tail moment in potassium dichromate-treated SGC-7901 cells. Accordingly, the cell rates of apoptosis and necrosis were also increased in URI knockdown cells treated with potassium dichromate at different concentrations. Together, these results suggest that URI is preventive for the oxidative stress and cell death induced by potassium dichromate, which potentially leads to cancer cell survival and therapeutic resistance.
ABSTRACT
Cervical cancer is a common and devastating female cancer worldwide. The etiology of cervical cancer has been largely attributed to human papillomavirus (HPV) infection and activation of the P13K/AKT/mTOR (mammalian target of rapamycin) pathway. However, the limited HPV-directed therapy, as well as therapeutic approach targeting P13K/AKT/mTOR pathway, has not yet been established or effective. A deeper understanding of cervical carcinogenesis and finding of novel candidate molecules for cervical cancer therapeutics is largely warranted. The unconventional prefoldin RPB5 interactor (URI or URI1), a known transcription factor involving the TOR signaling pathway, has recently been implicated a role in multiple tumorigenesis. We recently reported significant upregulation of URI in precancerous cervical intra-epithelial neoplasia (CIN) and invasive cervical cancer, suggesting its role in cervical carcinogenesis. However, the effect and underlying mechanism of URI in cervical cancer development have never been elucidated. Here, we aimed to investigate the in vitro effect of URI on cervical cancer using two cervical cancer cell lines CaSki and C33A, which are HPV-positive and HPV-negative respectively. We have shown that forced over-expression of URI in C33A and CaSki cells markedly promoted cell growth, while down-regulation of URI mediated by siRNA inhibited cell proliferation. We have found that URI over-expression enhanced resistance of cervical cancer cells to cisplatin. In contrast, knockdown of URI promoted apoptosis by influencing cell response to cisplatin, supporting URI as an oncogenic protein for cervical cancer cells. We have also shown that URI promoted the migration and invasive capacity of cervical cancer cells by up-regulation of Vimentin, a mesenchymal cell migration marker relating to the epithelial-mesenchymal transition (EMT) program. Our data support an important function of URI in the biological behavior of cervical cancer cells and provide novel mechanistic insights into the role of URI in cervical cancer progression and possibly, metastasis.
ABSTRACT
Prostate cancer remains the second leading cause of cancer death in men due to inefficiency of androgen deprivation therapy or androgen blockade. Endothelins (ETs) and the two endothelin receptor family members A and B (ETA and ETB) are known to play important roles in the progression of many malignancies, including prostate cancer. However, phase III clinical studies did not reach a unanimous conclusion regarding ETA receptor antagonists in prostate cancer treatment. Here, we provide a meta-analysis of clinical studies using ETA receptor antagonists to treat prostate cancer, especially the hormone refractory prostate cancer (HRPC). Data were extracted from nine studies that used Zibotentan or Atrasentan, two selective ETA receptor antagonists, to treat prostate cancer and meet the selection criteria. The results indicated that the overall survival (OS) and the progression-free survival (PFS) of patients treated with Zibotentan did not show significant difference with the patients treated with placebo (pooled hazard ratio (HR) for OS, 0.86, 95% CI 0.70-1.06; pooled HR for PFS, 0.98, 95% CI 0.91-1.06). No statistically significant difference was detected either as to the OS and PFS of patients between the Atrasentan treated group and the group treated with placebo (pooled HR for OS, 0.99, 95% CI 0.90-1.08; pooled HR for PFS, 0.94, 95% CI 0.86-1.02). Notably, the level of prostate-specific antigen (PSA) and the incidence of bone pain were significantly lower in the Atrasentan treated patients compared to the controls (pooled HR for time of PSA progression, 0.87, 95% CI 0.78-0.97; and pooled relative risk (RR) for bone pain, 0.68, 95% CI 0.48-0.97). In addition, increasing of PSA and bone alkaline phosphatase (BALP) were significantly delayed with Atrasentan treatment (P<0.05). Together, these data suggest that Atrasentan has an effect on cancer-related bone pain and skeletal-events in patients with prostate cancer.
ABSTRACT
Osteosarcoma (OS) is the most common pediatric bone cancer in children and young adults. Previous studies have suggested the importance of osteoblast activity in OS tumorigenesis and metastasis, as OS is characterized by abnormal bone formation, while osteoblast is the predominant cell type both in OS and in metastatic tumor tissues. RUNX2 is a known essential transcription factor for osteoblast differentiation. RUNX2 has also been linked to many human cancers, including bone cancers and cancer metastasis in bone. However, the view of RUNX2 during OS tumorigenesis has not been unanimous. In this manuscript, we reviewed the osteoblastic origin in OS etiology. The oncogenic property of RUNX2 in human OS studies was briefly summarized. RUNX2 may be involved in OS pathogenesis by regulating cell cycle controlling of (pre)-osteoblasts, which subsequently convert to OS cells. The roles and mechanisms of RUNX2 during OS metastasis and bone metastasis in target cancers (herein prostate and breast cancers), were as described. The potential involvement of Runx2 in multiple mouse OS models that use human OS cell lines (Xenografts), tumor suppressor genes p53 and Rb1 were also discussed. Finally, we updated some microRNAs studies and their relation with RUNX2 in OS pathogenesis. This review provides a comprehensive understanding of RUNX2's function during OS pathogenesis and will help with the research designing and strategy in controlling OS.
