CFL1 is Implicated in Chronic Myeloid Leukemia Response during Imatinib Therapy.

Cofilin (CFL1) is one critical member of the actin deploy family (ADF). Overexpression of CFL1 is associated with aggressive features and poor prognosis in malignancies. We evaluated the expression of CFL1 in patients with chronic myeloid leukemia in the chronic phase (CML-CP), acute myelocytic leukemia (AML) and healthy controls. The role of CFL1 in imatinib therapy was also investigated using cell line. We found that the expression of CFL1 was lower in CML patients than that in healthy controls, and was significantly upregulated after imatinib therapy (p<0.05). CML patients with lower CFL1 achieved higher Major molecular response (MMR) rate after 6 months of imatinib therapy (p<0.05). Cofilin, P-cofilin and F-actin, especially branched F-actin were all upregulated after imatinib therapy. The lower CFL1 expression before treatment may predicts a better response to imatinib. Imatinib affects F-actin remodeling in CML patients by regulating CFL1 expression and activity.

BMP and activin receptor membrane bound inhibitor: BAMBI has multiple roles in gene expression and diseases (Review).

BMP and activin membrane-bound inhibitor (BAMBI) is a transmembrane glycoprotein, known as a pseudo-receptor for TGFß, as, while its extracellular domain is similar to that of type I TGFß receptors, its intracellular structure is shorter and lacks a serine/threonine phosphokinase signaling motif. BAMBI can regulate numerous biological phenomena, including glucose and lipid metabolism, inflammatory responses, and cell proliferation and differentiation. Furthermore, abnormal expression of BAMBI at the mRNA and protein levels contributes to various human pathologies, including obesity and cancer. In the present review, the structure of BAMBI is briefly introduced and its associated signaling pathways and physiological functions are described. Understanding of BAMBI structure and function may contribute to knowledge regarding the occurrence of diseases, including obesity and diabetes, among others. The present review provides a theoretical foundation for the development of BAMBI as a potential biomarker or therapeutic target.

Proto-oncogene FAM83A contributes to casein kinase 1-mediated mitochondrial maintenance and white adipocyte differentiation.

Family with sequence similarity 83 A (FAM83A) is a newly discovered proto-oncogene that has been shown to play key roles in various cancers. However, the function of FAM83A in other physiological processes is not well known. Here, we report a novel function of FAM83A in adipocyte differentiation. We used an adipocyte-targeting fusion oligopeptide (FITC-ATS-9R) to deliver a FAM83A-sgRNA/Cas9 plasmid to knockdown Fam83a (ATS/sg-FAM83A) in white adipose tissue in mice, which resulted in reduced white adipose tissue mass, smaller adipocytes, and mitochondrial damage that was aggravated by a high-fat diet. In cultured 3T3-L1 adipocytes, we found loss or knockdown of Fam83a significantly repressed lipid droplet formation and downregulated the expression of lipogenic genes and proteins. Furthermore, inhibition of Fam83a decreased mitochondrial ATP production through blockage of the electron transport chain, associated with enhanced apoptosis. Mechanistically, we demonstrate FAM83A interacts with casein kinase 1 (CK1) and promotes the permeability of the mitochondrial outer membrane. Furthermore, loss of Fam83a in adipocytes hampered the formation of the TOM40 complex and impeded CK1-driven lipogenesis. Taken together, these results establish FAM83A as a critical regulator of mitochondria maintenance during adipogenesis.

TIGIT: A promising target to overcome the barrier of immunotherapy in hematological malignancies.

Immune evasion through up-regulating checkpoint inhibitory receptors on T cells plays an essential role in tumor initiation and progression. Therefore, immunotherapy, including immune checkpoint inhibitor targeting programmed cell death protein 1 (PD-1) and chimeric antigen receptor T cell (CAR-T) therapy, has become a promising strategy for hematological malignancies. T cell immunoreceptor with immunoglobulin and ITIM domain (TIGIT) is a novel checkpoint inhibitory receptor expressed on immune cells, including cytotoxic T cells, regulatory T cells, and NK cells. TIGIT participates in immune regulation via binding to its ligand CD155. Blockage of TIGIT has provided evidence of considerable efficacy in solid tumors in preclinical research and clinical trials, especially when combined with PD-1 inhibition. However, the mechanism and function of TIGIT in hematological malignancies have not been comprehensively studied. In this review, we focus on the role of TIGIT in hematological malignancies and discuss therapeutic strategies targeting TIGIT, which may provide a promising immunotherapy target for hematological malignancies.

Adipose-specific BMP and activin membrane-bound inhibitor (BAMBI) deletion promotes adipogenesis by accelerating ROS production.

With the improvement of people's living standards, the number of obese patients has also grown rapidly. It is reported that the level of oxidative stress in obese patients has significantly increased, mainly caused by the increase in reactive oxygen species (ROS) levels in adipose tissue. Studies have shown that the use of siRNA to interfere with bone morphogenetic protein and activin membrane-bound inhibitor (BAMBI) expression could promote adipocyte differentiation, and under hypoxic conditions, BAMBI could act as a regulator of HIF1α to regulate the polarity damage of epithelial cells. In view of these results, we speculated that BAMBI may regulate adipogenesis by regulating the level of ROS. In this study, we generated adipose-specific BAMBI knockout mice (BAMBI AKO) and found that compared with control mice, BAMBI AKO mice showed obesity when fed with high-fat diet, accompanied by insulin resistance, glucose intolerance, hypercholesterolemia, and increased inflammation in adipose tissue. Interestingly, adipose-specific deficiency of BAMBI could cause an increase in the expression level of Nox4, thereby promoting ROS production in cytoplasm and mitochondria and the DNA-binding activity of C/EBPß and ultimately promoting adipogenesis. Consistently, our findings indicated that BAMBI may be a reactive oxygen regulator to affect adipogenesis, thereby controlling obesity and metabolic syndrome.

MicroRNA-664-5p promotes myoblast proliferation and inhibits myoblast differentiation by targeting serum response factor and Wnt1.

MicroRNAs (miRNAs) are noncoding RNAs that regulate gene expression at the post-transcriptional level and are involved in the regulation of the formation, maintenance, and function of skeletal muscle. Using miRNA sequencing and bioinformatics analysis, we previously found that the miRNA miR-664-5p is significantly differentially expressed in longissimus dorsi muscles of Rongchang pigs. However, the molecular mechanism by which miR-664-5p regulates myogenesis remains unclear. In this study, using flow cytometry, 5-ethynyl-2'-deoxyuridine staining, and cell count and immunofluorescent assays, we found that cell-transfected miR-664-5p mimics greatly promoted proliferation of C2C12 mouse myoblasts by increasing the proportion of cells in the S- and G2-phases and up-regulating the expression of cell cycle genes. Moreover, miR-664-5p inhibited myoblast differentiation by down-regulating myogenic gene expression. In contrast, miR-664-5p inhibitor repressed myoblast proliferation and promoted myoblast differentiation. Mechanistically, using dual-luciferase reporter gene experiments, we demonstrated that miR-664-5p directly targets the 3'-UTR of serum response factor (SRF) and Wnt1 mRNAs. We also observed that miR-664-5p inhibits both mRNA and protein levels of SRF and Wnt1 during myoblast proliferation and myogenic differentiation, respectively. Furthermore, the activating effect of miR-664-5p on myoblast proliferation was attenuated by SRF overexpression, and miR-664-5p repressed myogenic differentiation by diminishing the accumulation of nuclear ß-catenin. Of note, miR-664-5p's inhibitory effect on myogenic differentiation was abrogated by treatment with Wnt1 protein, the key activator of the Wnt/ß-catenin signaling pathway. Collectively, our findings suggest that miR-664-5p controls SRF and canonical Wnt/ß-catenin signaling pathways in myogenesis.

Long noncoding RNA: multiple players in gene expression.

Previously considered as a component of transcriptional noise, long noncoding RNAs (lncRNAs) were neglected as a therapeutic target, however, recently increasing evidence has shown that lncRNAs can participate in numerous biological processes involved in genetic regulation including epigenetic, transcriptional, and post-transcriptional regulation. In this review, we discuss the fundamental functions of lncRNAs at different regulatory levels and their roles in metabolic balance. Typical examples are introduced to illustrate their diverse molecular mechanisms. The comprehensive investigation and identification of key lncRNAs will not only contribute to insights into diseases, such as breast cancer and type II diabetes, but also provide promising therapeutic targets for related diseases. [BMB Reports 2018; 51(6): 280-289].

Knockdown of ubiquitin D inhibits adipogenesis during the differentiation of porcine intramuscular and subcutaneous preadipocytes.

OBJECTIVES: Intramuscular fat (IMF) has a significant influence on porcine meat quality. Ubiquitin D (UBD) is involved in the management of diverse intracellular processes. However, its physiological functions in adipose cell differentiation and proliferation are still poorly defined. MATERIALS AND METHODS: Intramuscular and subcutaneous preadipocytes were isolated from the longissimus dorsi and neck subcutaneous deposits of Chinese native Guanzhong Black piglets (3-5 days old), respectively. Lentivirus with short hairpin RNA (shRNA) for UBD was applied to knockdown UBD expression. We used real-time PCR and Western blot analysis to detect gene expression. Lipid droplets were dyed with Oil Red O, and cell proliferation was assessed using flow cytometry, 5-ethynyl-2'-deoxyuridine incorporation and cell counting assays. RESULTS: Lipogenesis through the Akt/mTOR pathway was inhibited when preadipocytes were transfected with UBD shRNA. The expression of adipogenic genes and the number of lipid droplets were obviously diminished. Moreover, repression of UBD attenuated cell proliferation. UBD downregulation resulted in cell cycle arrest because of a decreased proportion of S-phase cells, and the expression of positive cell proliferation markers was significantly decreased. CONCLUSION: These observations illustrated that knockdown of UBD partially suppressed porcine intramuscular and subcutaneous preadipocyte adipogenesis through the Akt/mTOR signalling and inhibited cell proliferation, suggesting the essential role of UBD in the differentiation of preadipocytes.

Fibroblast-derived CXCL12/SDF-1α promotes CXCL6 secretion and co-operatively enhances metastatic potential through the PI3K/Akt/mTOR pathway in colon cancer.

AIM: To investigate the underlying mechanism by which CXCL12 and CXCL6 influences the metastatic potential of colon cancer and internal relation of colon cancer and stromal cells. METHODS: Western blotting was used to detect the expression of CXCL12 and CXCL6 in colon cancer cells and stromal cells. The co-operative effects of CXCL12 and CXCL6 on proliferation and invasion of colon cancer cells and human umbilical vein endothelial cells (HUVECs) were determined by enzyme-linked immunosorbent assay, and proliferation and invasion assays. The angiogenesis of HUVECs through interaction with cancer cells and stromal cells was examined by angiogenesis assay. We eventually investigated activation of PI3K/Akt/mTOR signaling by CXCL12 involved in the metastatic process of colon cancer. RESULTS: CXCL12 was expressed in DLD-1 cancer cells and fibroblasts. The secretion level of CXCL6 by colon cancer cells and HUVECs were significantly promoted by fibroblasts derived from CXCL12. CXCL6 and CXCL2 could significantly enhance HUVEC proliferation and migration (P < 0.01). CXCL6 and CXCL2 enhanced angiogenesis by HUVECs when cultured with fibroblast cells and colon cancer cells (P < 0.01). CXCL12 also enhanced the invasion of colon cancer cells. Stromal cell-derived CXCL12 promoted the secretion level of CXCL6 and co-operatively promoted metastasis of colon carcinoma through activation of the PI3K/Akt/mTOR pathway. CONCLUSION: Fibroblast-derived CXCL12 enhanced the CXCL6 secretion of colon cancer cells, and both CXCL12 and CXCL6 co-operatively regulated the metastasis via the PI3K/Akt/mTOR signaling pathway. Blocking this pathway may be a potential anti-metastatic therapeutic target for patients with colon cancer.

MicroRNA-432 targeting E2F3 and P55PIK inhibits myogenesis through PI3K/AKT/mTOR signaling pathway.

Skeletal muscle is the dominant executant in locomotion and regulator in energy metabolism. Embryonic myogenesis and postnatal muscle growth are controlled by a cascade of transcription factors and epigenetic regulatory mechanisms. MicroRNAs (miRNAs), a family of non-coding RNA of 22 nucleotides in length, post-transcriptionally regulates expression of mRNA by pairing the seed sequence to 3' UTR of target mRNA. Increasing evidence has demonstrated that miRNAs are important regulators in diverse myogenic processes. The profiling of miRNA expression revealed that miR-432 is more enriched in the longissimus dorsi of 35-day-old piglets than that of adult pigs. Our gain of function study showed that miR-432 can negatively regulate both myoblast proliferation and differentiation. Mechanically, we found that miR-432 is able to down-regulate E2F transcription factor 3 (E2F3) to inactivate the expression of cell cycle and myogenic genes. We also identified that phosphatidylinositol 3-kinase regulatory subunit (P55PIK) is another target gene of miR-432 in muscle cells. downregulation of P55PIK by miR-432 leads to inhibition of P55PIK-mediated PI3K/AKT/mTOR signaling pathway during differentiation. The blocking effect of miR-432 on this pathway can be rescued by insulin treatment. Taken together, our findings identified microRNA-432 as a potent inhibitor of myogenesis which functions by targeting E2F3 and P55PIK in muscle cells.

[Effect of polyunsaturated fatty acids ω-3 and ω-6 on angiogenesis formation in human gastric cancer].

OBJECTIVE: To investigate the effects of polyunsaturated fatty acids (PUFA) ω-3 and ω-6, and their middle metabolites PGE2 and PGE3 on angiogenesis formation of gastric cancer, and to explore associated mechanism. METHODS: The effects of ω-3, ω-6, PGE2, PGE3 on the proliferation and migration of human umbilical vein endothelial cell (HUVEC) were measured by proliferation and migration assay respectively. The angiogenesis assay in vivo was used to measure the effects of ω-3, ω-6, PGE2 and PGE3 on neovascularization. In all the assays, groups without ω-3, ω-6, PGE2 and PGE3 were designed as the control. RESULTS: With the increased concentration of ω-6 from 1 µmol/L to 10 µmol/L, the proliferation ability of HUVECs enhanced, and the number of migration cells also increased from 28.2±3.0 to 32.8±2.1, which was higher than control group (21.2±3.2) respectively (both P<0.05). With the increased concentration of ω-3 from 1 µmol/L to 10 µmol/L, the proliferation ability of HUVECs was inhibited, and the number of migration cells decreased from 15.8±2.0 to 11.0±2.1, which was lower than control group (22.1±3.0) respectively (both P<0.05). In the angiogenesis assay, compared with control group (standard number: 43 721±4 654), the angiogenesis ability of HUVECs was significantly enhanced by ω-6 in concentration-dependent manner (1 µmol/L group: 63 238±4 795, 10 µmol/L group: 78 166±6 123, all P<0.01). Meanwhile, with the increased concentration of ω-3 from 1 µmol/L to 10 µmol/L, the angiogenesis ability was significantly decreased from 30 129±3 102 to 20 012±1 541(all P<0.01). The proliferation and migration ability of HUVECs were significantly promoted by ω-6 metabolites PGE2 (P<0.05) in a concentration-dependent manner. In contrast, ω-3 metabolites PGE3 significantly inhibited the proliferation and migration ability of HUVECs in a concentration-dependent manner (all P<0.05). After rofecoxib (a COX-2 specific inhibitor) inhibited the expression of COX-2, the expression level of PGE2 was significantly decreased in a dose-dependent manner. In co-culture system, whose gastric cancer cells expressed positive COX-2, ω-6 could increase angiogenesis of gastric cancer cells(P<0.01), but ω-3 could inhibit such angiogenesis(P<0.01). In co-culture system, whose gastric cancer cells did not express COX-2, ω-3 could inhibit the angiogenesis of gastric cancer cells (P<0.05), but ω-6 had no effect on angiogenesis. CONCLUSIONS: The PUFA ω-6 can enhance the angiogenesis via the promotion of proliferation and migration of HUVECs, and COX-2 and PGE2 may play an important role in this process, whereas, the ω-3 can inhibit the angiogenesis through its middle metabolites PGE3 to inhibit the proliferation and migration of HUVECs. Results of this experiment may provide a new approach to inhibit and prevent the spread of gastric cancer.

MAT2B promotes adipogenesis by modulating SAMe levels and activating AKT/ERK pathway during porcine intramuscular preadipocyte differentiation.

Intramuscular fat (IMF) has been demonstrated as one of the crucial factors of livestock meat quality. The MAT2B protein with MAT2α catalyzes the formation of methyl donor S- adenosylmethionine (SAMe) to mediate cell metabolism including proliferation and apoptosis. However, the regulatory effect of MAT2B on IMF deposition is still unclear. In this study, the effect of MAT2B on adipogenesis and its potential mechanism during porcine intramuscular preadipocyte differentiation was studied. The results showed that overexpression of MAT2B promoted adipogenesis and significantly up-regulated the mRNA and protein levels of adipogenic marker genes including FASN, PPARγ and aP2, consistently, knockdown of MAT2B inhibited lipid accumulation and down-regulated the mRNA and protein levels of the above genes. Furthermore, flow cytometry and EdU-labeling assay indicated that MAT2B regulate adipogenesis was partly due to influence intracellular SAMe levels and further affect cell clonal expansion. Also, increased expression of MAT2B activated the phosphorylations of AKT and ERK1/2, whereas knockdown of MAT2B blocked AKT signaling and repressed the phosphorylation of ERK1/2. Moreover, the inhibitory effect of LY294002 (a specific PI3K inhibitor) on the activities of AKT and ERK1/2 was partially recovered by overexpression of MAT2B in porcine intramuscular adipocytes. Finally, Co-IP experiments showed that MAT2B can directly interact with AKT. Taken together, our findings suggested that MAT2B acted as a positive regulator through modifying SAMe levels as well as activating AKT/ERK signaling pathway to promote porcine intramuscular adipocyte differentiation.

[Effect of colon cancer cell-derived IL-1α on the migration and proliferation of vascular endothelial cells].

OBJECTIVE: To explore the effect of colon cancer cell-derived interleukin-1α on the migration and proliferation of human umbilical vein endothelial cells as well as the role of IL-1α and IL-1ra in the angiogenesis process. METHODS: Western blot was used to detect the expression of IL-1α and IL-1R1 protein in the colon cancer cell lines with different liver metastatic potential. We also examined how IL-1α and IL-1ra influence the proliferation and migration of umbilical vascular endothelial cells assessed by PreMix WST-1 assay and migration assay, respectively. Double layer culture technique was used to detect the effect of IL-1α on the proliferation and migration of vascular endothelial cells and the effect of IL-1ra on the vascular endothelial cells. RESULTS: Western blot analysis showed that IL-1α protein was only detected in highly metastatic colon cancer HT-29 and WiDr cells, but not in the lowly metastatic CaCo-2 and CoLo320 cells.Migration assay showed that there were significant differences in the number of penetrated cells between the control (17.9±3.6) and 1 ng/ml rIL-1α group (23.2±4.2), 10 ng/ml rIL-1α group (31.7±4.5), and 100 ng/ml rIL-1α group (38.6±4.9), showing that it was positively correlated with the increasing concentration of rIL-1α (P<0.01 for all). The proliferation assay showed that the absorbance values were 1.37±0.18 in the control group, and 1.79±0.14 in the 1 ng/ml rIL-1α group, 2.14±0.17 in the 10 ng/ml rIL-1α group, and 2.21±0.23 in the 100 ng/ml rIL-1α group, showing a positive correlation with the increasing concentration of rIL-1α(P<0.01 for all). IL-1ra significantly inhibited the proliferation and migration of vascular endothelial cells (P<0.01). The levels of VEGF protein were (1.697±0.072) ng/ml, (3.507±0.064)ng/ml and (4.139±0.039)ng/ml in the control, HUVECs+ IL-1α and HUVECs+ HT-29 co-culture system groups, respectively, showing a significant difference between the control and HUVECs+ 10 pg/ml rIL-1α groups and between the control and HUVECs+ HT-29 groups (P<0.01 for both). CONCLUSIONS: Our findings indicate that colon cancer cell-derived IL-1α plays an important role in the liver metastasis of colon cancer through increased VEGF level of the colon cancer cells and enhanced vascular endothelial cells proliferation, migration and angiogenesis, while IL-1ra can suppress the effect of IL-1α and inhibit the angiogenesis in colon cancer.