Mesenchymal Stromal Cell-Derived S100A8 Promotes Acute Myeloid Leukemia Progression Via ROS Signaling

Introduction: Mesenchymal stromal cell (MSC) is an important cell component in the bone marrow microenvironment. MSC-derived inflammatory factors regulate the progression of acute myeloid leukemia (AML) by regulating the signaling pathways in hematopoietic cells. S100A8 is an inflammatory factor which belong to the calcium-binding protein S100 family. In vivo animals experiments showed that increased expression of S100A8 in MSC was accompanied by increased proliferative MSCs, and decreased mature osteoblasts. MSC-derived S100A8 can also cause mitochondrial dysfunction in hematopoietic stem progenitor cells, induce oxidative stress response and DNA damage repair, that promotes the progression of myeloid dysplastic syndromes (MDS). However, whether MSC-derived S100A8 involved in AML development have not been reported. In this study, we attempted to elucidate the regulation of MSC-derived S100A8 on MSC itself as well as leukemia cells. Methods: Human MSCs were isolated from AML patients samples by whole bone marrow adherent culture, and the third to fifth passage cells were collected for analysis. The lentivirus vector carrying cDNA of S100A8 gene and the empty lentivirus vector were constructed and infected into MSCs,respectively. Cell cycle and apoptosis of MSCs were analysed by flow cytometry. Acute myeloid leukemia cell line Kasumi-1 was co-cultured with the two groups of mesenchymal stem cells in vitro for 3 days, respectively.cell cycle and apoptosis were analysed, and the cell proliferation was detected by Edu. The ROS levels of co-cultured Kasumi-1 cells were detected by flow cytometry. The apoptosis of kasumi-1 co-cultured cells treated with VP-16 for 48 hour was detected by flow cytometry. Results: The rate of G0 phase cell in S100A8-overexpressed MSCs was higher than in control group.The proliferation rate of Kasumi-1 cells was significantly increased S100A8 overexpressed group than in control after 72-h co-culture, while the apoptosis rate of Kasumi-1 cells was significantly decreased in S100A8 overexpressed group. Futhermore, the apoptosis rate of Kasumi-1 cells co-cultured with S100A8-overexpressed MSCs was markedly lower than in control group after exposed in vp-16 for 48 hour.The ROS level of Kasumi-1 cells co-cultured with S100A8-overexpressed MSCs were significantly increased than those of the control group. Conclusion: S100A8 derived from MSCs plays a critical role in progression and drug resistance of acute myeloid leukemia, by increasing the ROS levels of AML cells, that indicates S100A8 may serve as a potential novel therapeutic target in AML. Disclosures No relevant conflicts of interest to declare.

CHAF1A–PCNA interaction promotes cervical cancer progression via the PI3K/AKT/FoxO1 signaling pathway

Background An increasing number of studies demonstrate that histone chaperones play critical roles in tumorigenesis and development. In previous research, we confirmed that CHAF1A was highly expressed in cervical cancer (CC) and was correlated with poor prognosis. However, the biological function and specific mechanism of CHAF1A in the development of CC have not been reported. Methods CHAF1A knockdown in SiHa and HeLa.cells by lentivirus vector is verified by RT-PCR and Western blot analysis.CCK-8, flow cytometry assays, colony formation, cell migration assay and real-time cell analysis assay were performed to determine the cellular function of CHAF1A in CC.Tumor xenograft assay was conducted on nude mice to assess the effect of CHAF1A in vivo. Cell immunofluorescence and co-immunoprecipitation were applied to examine the interaction between CHAF1A and PCNA. Results We found that CHAF1A knockdown in SiHa and HeLa cell lines inhibited proliferation and promotedits apoptosis. Further research indicated that CHAF1A promoted proliferation and inhibited apoptosis in CC by activating the PI3K/Akt/FoxO1 signaling pathway. Moreover, CHAF1A directly interacts with PCNA and co-promotes CC progression. Conclusions The discovery of the mechanism of action of CHAF1A in CC may provide a new direction for the treatment of CC.

A Novel Long Noncoding RNA, Lnc-OAD, Is Required for Bone Morphogenetic Protein 2- (BMP-2-) Induced Osteoblast Differentiation

Long noncoding RNAs (lncRNAs) play very important roles in cell differentiation. Our recent study has demonstrated that a novel lncRNA named lnc-OAD modulated 3T3-L1 adipocyte differentiation. In the present study, we examined the roles of lnc-OAD in bone morphogenetic protein 2- (BMP-2-) induced osteoblast differentiation. Lnc-OAD expression was increased during BMP-2-induced osteoblast differentiation in C3H10T1/2 mesenchymal stem cells and MC3T3-E1 preosteoblast cells. Knockdown of lnc-OAD expression by specific siRNA remarkably decreased early osteoblast differentiation. In addition, stable knockdown of lnc-OAD by lentivirus vector also significantly inhibited late osteoblast differentiation and matrix mineralization in vitro. Conversely, stably overexpressed lnc-OAD with lentiviral vector accelerated osteoblast differentiation. Mechanistically, knockdown of lnc-OAD reduced significantly the phosphorylation of AKT and the expression of Osterix induced by BMP-2, while overexpression of lnc-OAD enhanced the phosphorylation of AKT and the expression of Osterix. Taken together, our study suggests that lnc-OAD plays an important role in modulating BMP-2-induced osteoblast differentiation via, at least in part, regulating the AKT-Osterix signaling axis.

RASSF1A regulates the abnormal cell proliferation in psoriasis via inhibition of YAP

Background: Psoriasis is a chronic, inflammatory skin disease with high incidence, treatment resistance, and high recurrence. Currently, the exact etiology and pathogenesis of psoriasis are unclear. The goal of this study was to characterize the effect of the upstream negative regulator RAS-association domain family 1A (RASSF1A) on Yes-associated protein (YAP) in psoriasis. Methods: Skin lesions of 22 patients with psoriasis and 19 controls with normal skin tissue were used. Human epidermal keratinocytes were stimulated with M5 (IL-1 α, IL-17, IL-22, TNF-α, oncostatin M) to establish the psoriatic cell model. Methylation inhibitor 5-Aza-CdR was prepared at different concentrations (5, 10, 20 μmol/L). Cells were infected with lentivirus vector overexpressing RASSF1A. Twenty-five 6–8-week-old female BALB/c mice were used to establish the psoriatic mouse model. Mice were randomly divided into five groups: control (Vaseline applied daily), psoriasis (imiquimod applied daily), and the three different 5-Aza-CdR concentrations (applied daily with imiquimod). Methylation-specific PCR (MSP) was used to detect RASSF1A methylation and immunohistochemistry was used to detect RASSF1A expression in skin lesions. After adding 5-Aza-CdR or lentivirus vector overexpressing RASSF1A, YAP expression, cell proliferation, cell cycle, apoptosis, inflammatory cytokines, and related signal pathway activity were investigated. Results: As RASSF1A methylation level increased, its expression in patients with psoriasis and mice with skin lesions decreased. Addition of 5-Aza-CdR or lentivirus vector overexpressing RASSF1A increased the expression of RASSF1A, reduced the expression of YAP and inflammatory cytokines, cell proliferation, as well as AKT, ERK, STAT3, and NF-κB signaling pathway activities, induced cell cycle arrest in G0/G1 phase, increased apoptosis, and improved skin lesions. Conclusions: RASSF1A inhibited the proliferation of psoriatic cells, induced apoptosis, and reduced the expression of inflammatory factors by inhibiting YAP expression. Based on our findings, targeted drugs that can inhibit RASSF1A methylation and increase its expression may be useful in the treatment of psoriasis.

RASSF1A Regulates the Abnormal Cell Proliferation in Psoriasis via Inhibition of YAP

Background: Psoriasis is a chronic, inflammatory skin disease with high incidence, treatment resistance, and high recurrence. Currently, the exact etiology and pathogenesis are unclear. The goal of this study was to characterize the role of the upstream negative regulator RAS-association domain family 1A (RASSF1A) on Yes-associated protein (YAP) in psoriasis.Methods: Skin lesions of 22 psoriasis patients and 19 normal skin tissue controls were used. Human epidermal keratinocytes were stimulated with M5 (IL-1 α, IL-17, IL-22, TNF-α, oncostatin M), to establish the psoriatic cell model. Methylation inhibitor, 5-Aza-CdR was prepared at different concentrations (5, 10, 20 μmol/L). Cells were infected with lentivirus vector overexpressing RASSF1A. Twenty-five 6-8-week-old female BALB/c mice were used to establish the psoriatic mouse model. Mice were randomly divided into five groups: control (Vaseline applied daily), psoriasis (imiquimod applied daily), and the three different 5-Aza-CdR concentrations (applied daily with imiquimod). Methylation specific PCR (MSP) was used to detect RASSF1A methylation, and immunohistochemistry was used to detect RASSF1A expression in skin lesions. After adding 5-Aza-CdR or lentivirus vector overexpressing RASSF1A, YAP expression, cell proliferation, cell cycle, apoptosis, inflammatory cytokines and related signal pathway activity were detected.Results: As RASSF1A methylation level increased, its expression in psoriasis patients and mice with skin lesions decreased. Addition of 5-Aza-CdR or lentivirus vector overexpressing RASSF1A increased the expression of RASSF1A, reduced the expression of YAP and inflammatory cytokines, cell proliferation, as well as AKT, ERK, STAT3 and NF-κB signaling pathway activities, induced cell cycle arrest in G0/G1 phase, increased apoptosis, and improved skin lesions.Conclusions: RASSF1A inhibited the proliferation of psoriatic cells, induced apoptosis, and reduced the expression of inflammatory factors by inhibiting YAP expression. Based on our findings, targeted drugs that can inhibit RASSF1A methylation and increase its expression may be useful in the treatment of psoriasis.

Validation of Enhancing Effects of Curcumin on Radiotherapy with F98/FGT Glioblastoma-Bearing Rat Model

Glioblastoma, the most common and aggressive brain tumor with low survival rate, is difficult to be cured by neurosurgery or radiotherapy. Mounting evidence has reported the anti-inflammatory and anticancer effects of curcumin on several types of cancer in preclinical studies and clinical trials. To our knowledge, there is no platform or system that could be used to effectively and real-timely evaluate the therapeutic efficacy of curcumin for glioblastoma multiforme (GBM). In this study, we constructed a lentivirus vector with triple-reporter genes (Fluc/GFP/tk) and transduced into rat F98 glioblastoma cells to establish an orthotopic F98/FGT glioma-bearing rat model. In the model, the therapeutic efficacies for curcumin alone, radiation alone, and their combination were evaluated via noninvasive bioluminescent imaging and overall survival measurements. At the cell level, curcumin is capable of causing a G2/M cell cycle arrest and sensitizing the F98 cells to radiation. In animal model, curcumin synergistically enhances the effects of radiotherapy on suppressing the growth of both transplanted glioma cells and in situ brain tumors, and extending the overall survival periods longer than those of curcumin alone and radiation alone treatments. In conclusion, we have demonstrated that curcumin may serve as a novel radiosensitizer to combine with radiotherapy using the triple-reporter F98/FGT animal model for effective and simultaneous evaluation of therapeutic efficacy.