L. Wang

Matrix softness regulates plasticity of tumour-repopulating cells via H3K9 demethylation and Sox2 expression

Tumour-repopulating cells (TRCs) are a self-renewing, tumorigenic subpopulation of cancer cells critical in cancer progression. However, the underlying mechanisms of how TRCs maintain their self-renewing capability remain elusive. Here we show that relatively undifferentiated melanoma TRCs exhibit plasticity in Cdc42-mediated mechanical stiffening, histone 3 lysine residue 9 (H3K9) methylation, Sox2 expression and self-renewal capability. In contrast to differentiated melanoma cells, TRCs have a low level of H3K9 methylation that is unresponsive to matrix stiffness or applied forces. Silencing H3K9 methyltransferase G9a or SUV39h1 elevates the self-renewal capability of differentiated melanoma cells in a Sox2-dependent manner. Mechanistically, H3K9 methylation at the Sox2 promoter region inhibits Sox2 expression that is essential in maintaining self-renewal and tumorigenicity of TRCs both in vitro and in vivo. Taken together, our data suggest that 3D soft-fibrin-matrix-mediated cell softening, H3K9 demethylation and Sox2 gene expression are essential in regulating TRC self-renewal.

Th17 cell plays a role in the pathogenesis of Hashimoto's thyroiditis in patients

Hashimotos thyroiditis (HT) has long been epidemiologically associated with excess iodine levels. However, the underlying immunological mechanisms still remain largely unexplored. Th17 cells are commonly recognized as playing vital roles in various autoimmune diseases. Here we show that intra-thyroid infiltrating Th17 cells and serum IL-17 levels were significantly increased in HT patients. However, the concentration of serum IL-17 was inversely correlated with patients residual thyroid function while the heterogeneously expressed thyroid IL-17 was directly correlated with local fibrosis. Administration of moderate high levels of iodine was found to facilitate the polarization of murine splenic naïve T cells into Th17 cells, whereas extreme high levels of iodine favored Th1 polarization and inhibited Treg development. These findings suggest that both Th1 and Th17 cells may be involved in the pathogenesis of HT and high levels of iodine may play a critical role in this process by modulating T cell differentiation.

Orientation of bluff body for designing efficient energy harvesters from vortex-induced vibrations

The characteristics and performances of four distinct vortex-induced vibrations (VIVs) piezoelectric energy harvesters are experimentally investigated and compared. The difference between these VIV energy harvesters is the installation of the cylindrical bluff body at the tip of cantilever beam with different orientations (bottom, top, horizontal, and vertical). Experiments show that the synchronization regions of the bottom, top, and horizontal configurations are almost the same at low wind speeds (around 1.5u2009m/s). The vertical configuration has the highest wind speed for synchronization (around 3.5u2009m/s) with the largest harvested power, which is explained by its highest natural frequency and the smallest coupled damping. The results lead to the conclusion that to design efficient VIV energy harvesters, the bluff body should be aligned with the beam for low wind speeds ( 2u2009m/s).

A Common Polymorphism near the ESR1 Gene Is Associated with Risk of Breast Cancer: Evidence from a Case-Control Study and a Meta-Analysis

Background Genome-wide association studies have reported that a polymorphism near the estrogen receptor gene (ESR1) (rs2046210) is associated with a risk of breast cancer, with the A allele conferring an increased risk. However, considering the controversial results from more recent replicated studies, we conducted a case-control study in an independent Chinese Han population and a meta-analysis to clarify the association of this polymorphism with breast cancer risk. Method and Findings A hospital-based case-control study including 461 cases and 537 controls from a Chinese Han population was conducted initially, and this study showed that the rs2046210 A allele was significantly associated with breast cancer risk, with an OR of 1.32 (95% CI u200a=u200a1.10–1.59). Subsequently, a meta-analysis integrating the current study and previous publications with a total of 53,379 cases and 55,493 controls was performed to further confirm our findings. Similarly, a significant association between this polymorphism and breast cancer risk was also observed in the overall population especially among Asians, with ORs for per A allele of 1.14 (95% CI u200a=u200a1.10–1.18) in the overall population and 1.27 (95% CI u200a=u200a1.23–1.31) in the Asian population. Conclusion Our results provide strong evidence to support that the common polymorphism near the ESR1 gene, rs2046210, is associated with an increased risk of breast cancer in Asian and European populations but not in Africans, although the biological mechanisms need to be further investigated.

Clinicopathological features of breast cancer with different molecular subtypes in chinese women

A retrospective study was performed to explore the relationship between molecular subtypes and clinicopathological features of breast cancer in Chinese women. Six hundred and twenty-eight Chinese women with breast cancer were classified into four molecular subtypes according to their estrogen receptor (ER), progesterone receptor (PR) and Her-2 status. The prevalence rate of each molecular subtype was analyzed. Relationship between the subtypes and clinicopathologic features was determined. The distribution of molecular subtypes was as follows: luminal A 46.5%, luminal B 17.0%, basal 21.5%, HER2/neu 15.0%. The subtypes had no significant difference under different menopausal status. However, in the age-specific groups, the age group of ≤35 years was more likely to get basal cell-like cancer (36.9%). Statistically significant differences were found among molecular subtypes by age, nuclear grade, tumor size, lymph node (LN) metastasis, tumor stage by American Joint Committee on Cancer (AJCC), radiotherapy but not by chemotherapy, types of surgery. After adjusting for several relative confounding factors, the basal subtype more likely had lower nodal involvement in both the incidence of LN metastasis (≥1 positive LN) and incidence of high-volume LN metastasis (≥4 positive LN). The HER2/neu subtype had higher nodal involvement in the incidence of high-volume LN metastases. After adjusting for relative confounding factors, the HER2/neu subtype more likely had higher AJCC tumor stages. It was suggested that there existed close relationship between molecular subtypes and clinicopathological features of breast cancer. In addition, the breast cancer subtypes have been proven to be an independent predictor of LN involvement and AJCC tumor stage. These findings are very important for understanding the occurrence, development, prognosis and treatment of breast cancer in Chinese population.SummaryA retrospective study was performed to explore the relationship between molecular subtypes and clinicopathological features of breast cancer in Chinese women. Six hundred and twenty-eight Chinese women with breast cancer were classified into four molecular subtypes according to their estrogen receptor (ER), progesterone receptor (PR) and Her-2 status. The prevalence rate of each molecular subtype was analyzed. Relationship between the subtypes and clinicopathologic features was determined. The distribution of molecular subtypes was as follows: luminal A 46.5%, luminal B 17.0%, basal 21.5%, HER2/neu 15.0%. The subtypes had no significant difference under different menopausal status. However, in the age-specific groups, the age group of ≤35 years was more likely to get basal cell-like cancer (36.9%). Statistically significant differences were found among molecular subtypes by age, nuclear grade, tumor size, lymph node (LN) metastasis, tumor stage by American Joint Committee on Cancer (AJCC), radiotherapy but not by chemotherapy, types of surgery. After adjusting for several relative confounding factors, the basal subtype more likely had lower nodal involvement in both the incidence of LN metastasis (≥1 positive LN) and incidence of high-volume LN metastasis (≥4 positive LN). The HER2/neu subtype had higher nodal involvement in the incidence of high-volume LN metastases. After adjusting for relative confounding factors, the HER2/neu subtype more likely had higher AJCC tumor stages. It was suggested that there existed close relationship between molecular subtypes and clinicopathological features of breast cancer. In addition, the breast cancer subtypes have been proven to be an independent predictor of LN involvement and AJCC tumor stage. These findings are very important for understanding the occurrence, development, prognosis and treatment of breast cancer in Chinese population.

Effects of notch-1 down-regulation on malignant behaviors of breast cancer stem cells

SummaryThis study examined the effect of Notch-1 signaling on malignant behaviors of breast cancer cells by regulating breast cancer stem cells (BCSCs). BCSCs were enriched by using serum-free medium and knocked out of Notch-1 by using a lentiviral vector. Real-time polymerase chain reaction (RT-PCR) and Western blotting were used to detect the Notch-1 expression levels in breast cancer cell lines and BCSCs, and flow cytometry to detect the proportion of BCSCs in BCSC spheres. The BCSC self-renewal, migration, invasion, and tumorigenicity were examined by the tumor microsphere-forming assay and transwell assay and after xenotransplantation. The results showed that the Notch-1 silencing reduced the number of BCSC spheres, the proportion of BCSCs, and the number of cells penetrating through the transwell membrane. It also decreased the size of tumors that were implanted in the nude mice. These results suggest that Notch-1 signaling is intimately linked to the behaviors of BCSCs. Blocking Notch-1 signaling can inhibit the malignant behaviors of BCSCs, which may provide a promising therapeutical approach for breast cancer.This study examined the effect of Notch-1 signaling on malignant behaviors of breast cancer cells by regulating breast cancer stem cells (BCSCs). BCSCs were enriched by using serum-free medium and knocked out of Notch-1 by using a lentiviral vector. Real-time polymerase chain reaction (RT-PCR) and Western blotting were used to detect the Notch-1 expression levels in breast cancer cell lines and BCSCs, and flow cytometry to detect the proportion of BCSCs in BCSC spheres. The BCSC self-renewal, migration, invasion, and tumorigenicity were examined by the tumor microsphere-forming assay and transwell assay and after xenotransplantation. The results showed that the Notch-1 silencing reduced the number of BCSC spheres, the proportion of BCSCs, and the number of cells penetrating through the transwell membrane. It also decreased the size of tumors that were implanted in the nude mice. These results suggest that Notch-1 signaling is intimately linked to the behaviors of BCSCs. Blocking Notch-1 signaling can inhibit the malignant behaviors of BCSCs, which may provide a promising therapeutical approach for breast cancer.

Decreased expression of EZH2 reactivates RASSF2A by reversal of promoter methylation in breast cancer cells.

EZH2, the catalytic subunit of polycomb repressor complex 2, has oncogenic properties, whereas RASSF2A, a Ras association domain family protein, has a tumor suppressor role in many types of human cancer. However, the interrelationship between these two genes remains unclear. Here, we showed that the downregulation of EZH2 reduces CpG island methylation of the RASSF2A promoter, thereby leading to increased RASSF2A expression. Our findings also showed that knockdown of EZH2 increased RASSF2A expression in the human breast cancer cell line MCF‐7 in cooperation with DNMT1. This was similar to the effect of 5‐Aza‐CdR, a DNA methylation inhibitor that reactivates tumor suppressor genes and activated RASSF2A expression in our study. The EZH2 inhibitor DZNep markedly suppressed the proliferation, migration, and invasion of MCF‐7 cells treated with ADR and TAM. EZH2 inhibits the expression of tumor suppressor gene RASSF2A via promoter hypermethylation. Thus, it plays an important role in tumorigenesis and is a potential therapeutic target for the treatment of breast cancer.

Changes in circulating endothelial progenitor cells predict responses of multiple myeloma patients to treatment with bortezomib and dexamethasone

Four cycles of chemotherapy are required to assess responses of multiple myeloma (MM) patients. We investigated whether circulating endothelial progenitor cells (cEPCs) could be a biomarker for predicting patient response in the first cycle of chemotherapy with bortezomib and dexamethasone, so patients might avoid ineffective and costly treatments and reduce exposure to unwanted side effects. We measured cEPCs and stromal cell-derived factor-1α (SDF-1α) in 46 MM patients in the first cycle of treatment with bortezomib and dexamethasone, and investigated clinical relevance based on patient response after four 21-day cycles. The mononuclear cell fraction was analyzed for cEPC by FACS analysis, and SDF-1α was analyzed by ELISA. The study population was divided into 3 groups according to the response to chemotherapy: good responders (n=16), common responders (n=12), and non-responders (n=18). There were no significant differences among these groups at baseline day 1 (P>0.05). cEPC levels decreased slightly at day 21 (8.2±3.3 cEPCs/μL) vs day 1 (8.4±2.9 cEPCs/μL) in good responders (P>0.05). In contrast, cEPC levels increased significantly in the other two groups (P<0.05). SDF-1α changes were closely related to changes in cEPCs. These findings indicate that change in cEPCs at day 21 in the first cycle might be considered a noninvasive biomarker for predicting a later response, and extent of change could help decide whether to continue this costly chemotherapy. cEPCs and the SDF-1α/CXCR4 axis are potential therapeutic targets for improved response and outcomes in MM patients.

Evaluation of a father and son with atypical chronic myeloid leukemia with SETBP1 mutations and a review of the literature

We report the case of a father and son diagnosed with atypical chronic myeloid leukemia (aCML). Both patients harbored SETBP1 mutations, which are present in 24.3% of aCML patients. Moreover, both shared the variant encoding p.Pro737His, but the aCML severity was greater in the son because of the presence of two other missense mutations causing p.Asp868Asn and p.Ser885Arg alterations. SETBP1 mutations may be associated with an adverse prognosis, so their detection would help in the diagnosis of aCML and the determination of a patients prognosis.