BackgroundCancer stem cells (CSCs) are correlated with the initiation, chemoresistance and relapse of tumors. Notch pathway has been reported to function in CSCs maintenance, but whether it is involved in renal cell carcinoma (RCC) CSCs maintaining stemness remain unclear. This study aims to explore the effect of Notch pathway on stemness of CSCs in RCC and the underlying mechanisms.MethodsThe CD133+/CD24+ cells were isolated from RCC ACHN and Caki-1 cell line using Magnetic-activated cell sorting and identified by Flow cytometry analysis. RT-PCR and immunoblot analyses were used for determining the stemness maker expression. The effect of Notch pathway on function of CSCs was assessed by self-renewal ability, chemosensitivity, invasive and migratory ability tumorigenicity in vivo using soft agar colony formation assay, sphere-forming assay, MTT assay, Transwell assay.ResultsHere, we found that the sorted CD133+/CD24+cells possessed elevated stemness maker CTR2, BCL-2, MDR1, OCT-4, KLF4, compared with parental cells, as well as enhanced self-renewal ability, stronger resistance to cisplatin and sorafenib, increased invasion and migration, and higher tumorigenesis in vivo, suggesting the CD133+/CD24+ cells have the stem-like characteristics of CSCs and thus identified as RCC CSCs. Then the enhanced notch1, notch2, Jagged1, Jagged2, DLL1 and DLL4 expression were detected in RCC CSCs and blockage of Notch1 or notch2 using pharmacological inhibitor MRK-003 or its endogenous inhibitor Numb resulted in loss of its stemness features: self-renewal, chemoresistance, invasive and migratory potential, and tumorigenesis in vivo. Moreover, it is confirmed that overexpression of notch1 up-regulated CXCR4 inRCC CSCs and augmented SDF-1-induced chemotaxis in RCC CSCs in vitro, which could be rescued when treatment of CXCR4 inhibitor, suggesting that notch signaling promotes the chemotaxis of RCC CSCs by SDF-1/CXCR4 axis.ConclusionsOur results provide a new mechanism of RCC CSCs maintaining stemness via notch pathway as well as a potential therapeutic target in human RCC.

BackgroundLong noncoding RNAs (lncRNA) contained in exosomes have been recognized as promising stable biomarkers in cancers. H19 is a well-known oncogenic lncRNA, but whether extracellular H19 is contained in exosomes and the clinical significance of exosomal H19 are poorly understood. The aim of this study was to assess serum-derived exosomal H19 lncRNA as a cancer predictive marker.Material/MethodsExosomes from serum of bladder cancer (BC) patients were isolated using the ExoQuick purification method and identified using transmission electron microscopy and nanoparticle tracking analysis. RT-qPCR was used for the measurement of H19 expression in serum or tissue samples.ResultsSerum H19 was little influenced by the treatment of RNase A alone but was dramatically downregulated when treated with RNase A and Triton ×100 simultaneously. The concentration of H19 was significantly higher in serum exosomes than in exosome-depleted supernatants in serum. Then, we validated that exosomal H19 is stable in serum by exposing serum samples to prolonged conditions of room temperature, 4°C, multiple freeze-thaw cycles, and low/high pH. Serum exosomal H19 of BC patients was positively correlated with total H19 level in paired BC tissues, and exosomal H19 was significantly downregulated in postoperative samples when compared to the paired preoperative samples. In addition, exosomal H19 level was significantly increased in serum of BC patients when compared to healthy people and benign disease patients. More importantly, Kaplan-Meier survival curve analysis showed that higher serum exosomal H19 level in BC patients was correlated with poorer survival.ConclusionsDetection of serum exosomal H19 shed light on using exosomal lncRNAs as a noninvasive diagnostic and prognostic biomarker for BC patients.

HMGB1 is associated with human cancers and is an activator of autophagy which mediates chemotherapy resistance. We here show that the mRNA levels of HMGB1 are high in leukemia cells and it is involved in the progression of childhood chronic myeloid leukemia (CML). HMGB1 decreases the sensitivity of human myeloid leukemia cells K562 to anti-cancer drug induced death through up-regulating the autophagy pathway, which is confirmed by the observation with an increase in fusion of autophagosomes and autophagolysosomes. When overexpressing HMGB1, both mRNA levels of Beclin-1, VSP34 and UVRAG which are key genes involved in mammalian autophagy and protein levels of p-Bcl-2 and LC3-II are increased. Luciferase assays document that over-expression of HMGB1 increases the transcriptional activity of JNK and ERK, which may be silenced by siRNA. The results suggest that HMGB1 regulates JNK and ERK required for autophagy, which provides a potential drug target for therapeutic interventions in childhood CML. [BMB reports 2011; 44(9): 601-606]

As prebiotics, galacto-oligosaccharides (GOSs) can improve the intestinal flora and have important applications in medicine. β-galactosidases could promote the synthesis of GOSs in lactose and catalyze the hydrolysis of lactose. In this study, a new β-galactosidase gene (gal2A), which belongs to the glycoside hydrolase family 2, was cloned from marine bacterium Alteromonas sp. QD01 and expressed in Escherichia coli. The molecular weight of Gal2A was 117.07 kDa. The optimal pH and temperature of Gal2A were 8.0 and 40 °C, respectively. At the same time, Gal2A showed wide pH stability in the pH range of 6.0–9.5, which is suitable for lactose hydrolysis in milk. Most metal ions promoted the activity of Gal2A, especially Mn2+ and Mg2+. Importantly, Gal2A exhibited high transglycosylation activity, which can catalyze the formation of GOS from milk and lactose. These characteristics indicated that Gal2A may be ideal for producing GOSs and lactose-reducing dairy products.

High mobility group box 1 (HMGB1), which is released by activated immune cells and necrotic cells, has properties similar to those of pro-inflammatory cytokines. Cardiopulmonary bypass (CPB) induces systemic inflammation and aortic cross-clamping induces myocardial ischemia. This study was conducted to observe the dynamic changes of HMGB1 and tumor necrosis factor (TNF)-α levels during CPB and to analyze their clinical significance. A total of 78 cases of American Society of Anesthesiologists (ASA) grade II–IV undergoing elective valve replacement under CPB were included in this study. Blood and urine samples were collected after anesthesia prior to surgery (T1), before aortic cross-clamping (T2), after CPB (T3) and on the first day after surgery (T4), as well as the second (T5) and third (T6) day after surgery for determination of the levels of HMGB1, TNF-α, alanine aminotransferase (ALT), creatinine (Cr), blood urea nitrogen (BUN), N-acetyl-β-D-glucosamidase (NAG) and β2-microglobulin (β2-MG). Results revealed that: i) the serum levels of HMGB1 elevated as early as T1, increased until reaching a peak at T3, then decreased to a lower level at T4; ii) the serum level of TNF-α was low at T1, gradually increased in a similar manner to HMGB1, then decreased following CPB and reached the lowest point at T5; and iii) the levels of HMGB1 were positively correlated with serum TNF-α and serum ALT at T3. In conclusion, HMGB1 levels may be used as an indicator of inflammation and may be a novel target for controlling inflammation during CPB. The optimal treatment time is T3 (after CPB).

BackgroundMatrix mineralization is a key stage in bone formation involving in many bone-specific genes and signaling pathways. Emerging evidence indicate that long non-coding RNA (lncRNA) and microRNAs (miRNAs) play crucial roles in regulating the mineralization process of osteoblasts. This study aims to characterize the function and mechanism of lncRNA H19/miR-185-5p/IGF1 axis in modulating matrix mineralization of osteoblasts.ResultsH19 and IGF1 were highly expressed while miR-185-5p was lowly expressed in mineralized cells. Knocking down H19 inhibited matrix mineralization of osteoblasts, yet miR-185-5p had opposite effects. Moreover, H19 directly targeted miR-185-5p, whereas miR-185-5p repressed IGF1 expression. Meanwhile, miR-185-5p inhibition compensated the suppression of the matrix mineralization in osteoblasts by H19 knockdown.ConclusionsThe findings of this study showed that lncRNA H19 was upregulated in mineralized osteoblasts and promoted matrix mineralization through miR-185-5p/IGF1 axis in osteoblasts for the first time. This study may provide a new perspective for the diagnosis and treatment of diseases related to bone metabolism.

Background The impact of fibrinolysis-first strategy on outcomes of patients with ST-segment-elevation myocardial infarction (STEMI) during the COVID-19 pandemic was unknown. Methods Data from STEMI patients presenting to Fuwai Hospital from January 23 to April 30, 2020 were compared with those during the equivalent period in 2019. The primary end-point was net adverse clinical events (NACE; a composite of death, non-fatal myocardial reinfarction, stroke, emergency revascularization, and bleeding over BARC type 3). The secondary outcome was a composite of recurrent ischaemia, cardiogenic shock, and exacerbated heart failure. Results The final analysis included 164 acute STEMI patients from 2020 and 240 from 2019. Eighteen patients (20.2% of those with indications) received fibrinolysis therapy in 2020 with a median door-to-needle time of 60.0 (43.5, 92.0) minutes. Patients in 2020 underwent primary PCI less frequently than their counterparts (14 [14.2%] vs. 144 [86.8%] in 2019, P < 0.001), and had a longer median door-to-balloon time (175 [121,213] minutes vs. 115 [83, 160] minutes in 2019, P = 0.009). Patients were more likely to undergo elective PCI (86 [52.4%] vs. 28 [11.6%] in 2019, P < 0.001). The in-hospital NACE was similar between 2020 and 2019 (14 [8.5%] vs. 25 [10.4%], P = 0.530), while more patients developed a secondary outcome in 2020 (20 [12.2%] vs. 12 [5.0%] in 2019, P = 0.009). Conclusions The fibrinolysis-first strategy during the COVID-19 pandemic was associated with a lower rate of timely coronary reperfusion and increased rates of recurrent ischaemia, cardiogenic shock, and exacerbated heart failure. However, the in-hospital NACE remained similar to that in 2019.

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