Id2 regulates the proliferation of squamous cell carcinoma in vitro via the NF-κB/Cyclin D1 pathway

Case report: Variability in clinical manifestations within a family with incontinentia pigmenti

Diagnosing skin diseases in children can be a complex interdisciplinary problem. Incontinentia pigmenti (IP), also known as Bloch-Sulzberger syndrome, is a rare hereditary genodermatosis related to a mutation in the IKBKG gene. We present a family case of IP described from the perspective of various specialists, including dermatologists, oncologists, geneticists, dentists, and trichologists. The peculiarity of this case is the development of squamous cell carcinoma (SCC) on the shin of a 10-year-old female patient with IP. The patient had a positive family history: her mother and two sisters also displayed clinical manifestations of IP with involvement of skin, teeth and hair. The presence of exons 4-10 deletion in the IKBKG gene in all affected females was confirmed by detailed genetic evaluation using long-range PCR, and also high degree of X-chromosome inactivation skewing was demonstrated. The family underwent a comprehensive examination and was followed up for 2 years with successful symptomatic treatment of dermatologic manifestations. Recommendations were also made regarding dental and hair problems. By the end of the follow-up period, patients had stabilized, with the exception of a 36-year-old mother who developed generalized morphea. The study demonstrates the varying expressiveness of clinical symptoms among family members and emphasizes the importance of timely diagnosis for effective management of patients with IP.

SMURF2 facilitates ubiquitin-mediated degradation of ID2 to attenuate lung cancer cell proliferation

SMAD-specific E3 ubiquitin protein ligase 2 (SMURF2) functions as either a tumor promoter or tumor suppressor in several tumors. However, the detailed effect of SMURF2 on non-small cell lung cancer has not been fully understood. In this study, SMURF2 expression and its diagnostic value were analyzed. Co-Immunoprecipitation (Co-IP), proximity ligation assay (PLA), chromatin immunoprecipitation (ChIP) and nude mice tumor-bearing model were applied to further clarify the role of SMURF2 in lung cancer. SMURF2 expression was reduced in the tumor tissues of patients with NSCLC and high SMURF2 expression was significantly correlated with favorable outcomes. Furthermore, the overexpression of SMURF2 significantly inhibited lung cancer cell progression. Mechanistically, SMURF2 interacted with inhibitor of DNA binding 2 (ID2), subsequently promoting the poly-ubiquitination and degradation of ID2 through the ubiquitin-proteasome pathway. Downregulated ID2 in lung cells dissociates endogenous transcription factor E2A, a positive regulator of the cyclin-dependent kinase inhibitor p21, and finally induces G1/S arrest in lung cancer cells. This study revealed that the manipulation of ID2 via SMURF2 may control tumor progression and contribute to the development of novel targeted antitumor drugs.

The placenta epigenome-brain axis: placental epigenomic and transcriptomic responses that preprogram cognitive impairment

Aim: The placenta-brain axis reflects a developmental linkage where disrupted placental function is associated with impaired neurodevelopment later in life. Placental gene expression and the expression of epigenetic modifiers such as miRNAs may be tied to these impairments and are understudied. Materials & methods: The expression levels of mRNAs (n = 37,268) and their targeting miRNAs (n = 2083) were assessed within placentas collected from the ELGAN study cohort (n = 386). The ELGAN adolescents were assessed for neurocognitive function at age 10 and the association with placental mRNA/miRNAs was determined. Results: Placental mRNAs related to inflammatory and apoptotic processes are under miRNA control and associated with cognitive impairment at age 10. Conclusion: Findings highlight key placenta epigenome-brain relationships that support the developmental origins of health and disease hypothesis.

Inhibitor of DNA binding 2 knockdown inhibits the growth and liver metastasis of colorectal cancer

BACKGROUND

Liver metastasis of colorectal cancer (CRC) remains high mortality and the mechanism is still unknown. Here we investigated the effects of inhibitor of DNA binding 2 (Id2) on growth and liver metastasis of CRC.

METHODS

qPCR and western blotting were used to demonstrate mRNA and protein expressions in Id2-knockdown HCT116 cells. Cell growth was observed by cell proliferation assay, colony formation assay and flow cytometry. Cell migration and invasion were observed with wound healing assay and transwell migration and invasion assay. The effects of Id2 knockdown on tumor growth and liver metastasis in vivo were evaluated respectively with subcutaneous tumor model and colorectal liver metastasis model by injecting HCT116 cells into the mesentery triangle of cecum in mice.

RESULTS

Id2 overexpression was found in CRC cell lines. Id2 knockdown resulted in a reduction in the proliferation, colony formation, migration and invasion of HCT116 cells. The suppression of cell proliferation was accompanied by the cell cycle arrest in the G0/G1 phase with down-regulation of Cyclin D1, Cyclin E, p-Cdk2/3, Cdk6, p-p27 and up-regulation of p21 and p27. Id2 knockdown reversed epithelial-mesenchymal transition (EMT) through increasing E-Cadherin and inhibiting N-Cadherin, Vimentin, β-catenin, Snail and Slug. Id2 was also found to inhibit CRC metastasis via MMP2, MMP9 and TIMP-1. Furthermore, Id2 knockdown suppressed CRC liver metastasis in vivo.

CONCLUSION

Id2 promotes CRC growth through activation of the PI3K/AKT signaling pathway, and triggers EMT to enhance CRC migration and invasion.

The regulation of cyclin D promoters - review

Cyclins are key regulators of cell cycle progression and survival. Particularly cyclins D (cyclin D1, D2, and D3) act in response to the mitogenic stimulation and are pivotal mediators between proliferative pathways and the nuclear cell cycle machinery. Dysregulation of cyclins expression results in impaired development, abnormal cell growth or tumorigenesis. In this review we summarize current knowledge about regulatory role of the cyclin D promoters, transcriptional factors: regulators, co-activators and adaptor proteins necessary to their activation. We focused on the intracellular signaling pathways vital to cell growth, differentiation and apoptosis including transcription factor families: activator protein 1 (AP1), nuclear factor (NFκB), signal transducer and activator of transcription (STAT), cAMP response element-binding protein (CREB) and Sp/NF-Y, with a special insight into the tissue specific cyclin representation.

Single-cell RNA sequencing reveals cellular and molecular immune profile in a Pembrolizumab-responsive PD-L1-negative lung cancer patient

High expression of PD-L1 predicts PD-1/PD-L1 inhibitor benefit, meanwhile a few PD-L1-negative patients still benefit from these drugs. In this study, we aimed to explore the underlying cellular and molecular characteristics via single-cell sequencing. Before and after treatment with Pembrolizumab, peripheral blood mononuclear cells (PBMCs) were isolated via Ficoll gradient. Thereafter, single-cell RNA sequencing was performed, and clinical significance was validated with The Cancer Genome Atlas (TCGA) cohort. All 3423 cells of 16 clusters were classified into eight cell types, including NKG7+ T, NKG7+ NK, Naïve T, CDC1C+ dendritic cells, CD8+ T cells, B cells, macrophages and erythrocytes. Cell proportion, the clinical significance of differentially expressed genes and significant pathways of NKG7+ T, NKG7+ NK, Naïve T and CD8+ T cells were analyzed. Ubiquitin-mediated proteolysis/cell cycle/natural killer cell-mediated cytotoxicity were identified as PD-1 blockage-responsive pathways in NKG7+ NK cells. Apoptosis/Th1 and Th2 cell differentiation were proposed as Pembrolizumab-affected pathways in NKT cells. In gene level, ID2, PIK3CD, UQCR10, MATK, MZB1, IL7R and TRGC2 showed a significant correlation with PD-1 expression after TCGA dataset validation, which could possess potential as predictive markers for patients with PD-L1-negative lung squamous cell carcinoma who can benefit from Pembrolizumab.

Microarray and pathway analysis of two COMMA-Dβ derived clones reveal important differences relevant to their developmental capacity in-vivo

Microarray technologies were used to analyze transcriptomes from Comma-Dβ and clonal derivatives, SP3 (Lobule-competent) and NSP2 (Lobule-incompetent), during different mouse mammary growth phases: in-vitro, in-vivo 5-weeks, and in-vivo 12-weeks. A differentially expressed gene (DEG) algorithm was used to enrich for genes associated with cellular proliferation, differentiation, cell cycle regulation, and carcinogenesis. A pairwise comparison analysis, of SP3 vs. NSP2 in-vitro, revealed a total of 45 DEGs significantly up-regulated in SP3. Of the 45 DEGs, only Ccnd1 (Cyclin D1), Id2 (Inhibitor of DNA binding 2) and Sox9 (SRY Box 9) were identified to be associated with cellular proliferation, regulation of G1/S mitotic cell cycle, mammary gland and alveolar development in SP3. During the regenerative growth phase, in-vivo 5-weeks, we identified a total of 545 DEGs. 308 DEGs, of the 545 DEGs, were significantly up-regulated and 237 DEGs were significantly down-regulated in SP3 vs. NSP2. In addition, we identified 9 DEGs significantly up-regulated, within SP3's cell cycle pathway and a persistent overexpression of Cyclin D1, Id2, and Sox9, consistent with our in-vitro study. During the maintenance phase, in-vivo 12-weeks, we identified 407 DEGs. Of these, 336 DEGs were up-regulated, and 71 were down-regulated in SP3 vs. NSP2. Our data shows 15 DEGs significantly up-regulated, simultaneously, affecting 8 signal transducing carcinogenic pathways. In conclusion, increased expression of Cyclin D1, Id2 and Sox9 appear to be important for lobular genesis in SP3. Also, in-vivo 12 week displays increase expression of genes and pathways, involved in tumorigenesis.

PARP1 rs1805407 Increases Sensitivity to PARP1 Inhibitors in Cancer Cells Suggesting an Improved Therapeutic Strategy

Personalized cancer therapy relies on identifying patient subsets that benefit from a therapeutic intervention and suggest alternative regimens for those who don't. A new data integrative approach, based on graphical models, was applied on our multi-modal -omics, and clinical data cohort of metastatic melanoma patients. We found that response to chemotherapy is directly linked to ten gene expression, four methylation variables and PARP1 SNP rs1805407. PARP1 is a DNA repair gene critical for chemotherapy response and for which FDA-approved inhibitors are clinically available (olaparib). We demonstrated that two PARP inhibitors (ABT-888 and olaparib) make SNP carrier cancer cells of various histologic subtypes more sensitive to alkylating agents, but they have no effect in wild-type cells. Furthermore, PARP1 inhibitors act synergistically with chemotherapy in SNP carrier cells (especially in ovarian cancer for which olaparib is FDA-approved), but they are additive at best in wild-type cancer cells. Taken together, our results suggest that the combination of chemotherapy and PARP1 inhibition may benefit the carriers of rs1805407 in the future and may be used in personalized therapy strategies to select patients that are more likely to respond to PARP inhibitors.

Inhibitor of binding/differentiation 2 (Id2) is regulated by CCAAT/enhancer-binding protein-α (C/EBPα) and promotes the proliferation of hepatocellular carcinoma

Inhibitor of DNA binding/differentiation (Id2) is an important regulator involved in the initiation and progression of cancer. However, the function and mechanism of the regulation of Id2 in hepatocellular carcinoma (HCC) was unclear. In the present study, we found that the overexpression of Id2 increased HCC cell proliferation in vitro and in vivo. Knockdown of Id2 inhibited HCC cell proliferation in vitro and in vivo. Furthermore, knockdown of Id2 enhanced sorafenib-induced apoptosis in HCC. Conversely, overexpression of Id2 weakened sorafenib-induced apoptosis in HCC. In addition, the transcription factor CCAAT/enhancer-binding protein alpha (C/EBPα) bound to the Id2 promoter and decreased its expression in HCC cells. Therefore, all results suggest that Id2 promotes the proliferation of HCC cells by inhibiting cell apoptosis. Id2 may serve as a potential target in HCC therapy.

CaMKII-mediated Beclin 1 phosphorylation regulates autophagy that promotes degradation of Id and neuroblastoma cell differentiation

Autophagy is a degradative pathway that delivers cellular components to the lysosome for degradation. The role of autophagy in cell differentiation is poorly understood. Here we show that CaMKII can directly phosphorylate Beclin 1 at Ser90 to promote K63-linked ubiquitination of Beclin 1 and activation of autophagy. Meanwhile, CaMKII can also promote K63-linked ubiquitination of inhibitor of differentiation 1/2 (Id-1/2) by catalyzing phosphorylation of Id proteins and recruiting TRAF-6. Ubiquitinated Id-1/Id-2 can then bind to p62 and be transported to autolysosomes for degradation. Id degradation promotes the differentiation of neuroblastoma cells and reduces the proportion of stem-like cells. Our study proposes a mechanism by which autophagic degradation of Id proteins can regulate cell differentiation. This suggests that targeting of CaMKII and the regulation of autophagic degradation of Id may be an effective therapeutic strategy to induce cell differentiation in neuroblastoma.

Neuroblastoma cell differentiation is regulated by Id proteins. Here, the authors show that CaMKII-mediated phosphorylation of Beclin 1 can activate K63-linked ubiquitination and autophagic degradation of Id proteins uncovering a role for autophagy in cell differentiation.

LncRNA H19 regulates ID2 expression through competitive binding to hsa-miR-19a/b in acute myelocytic leukemia

Acute myelocytic leukemia (AML) is the most common type of acute leukemia. Long non‑coding RNAs (lncRNAs) serve an important role in regulating gene expression through chromatin modification, transcription and post‑transcriptional processing. LncRNA H19 was considered as an independent prognostic marker for patients with tumors. The expression of lncRNA H19 was identified to be significantly upregulated in bone marrow samples from patients with AML‑M2. Furthermore, it was demonstrated that the knockdown of lncRNA H19 resulted in increased expression of hsa‑microRNA (miR)‑19a/b and decreased expression of inhibitor of DNA binding 2 (ID2) in AML cells. The knockdown of lncRNA H19 inhibited the proliferation of AML cells in vitro, which could be partially reversed by ID2 overexpression. Furthermore, the results of the bioinformatic analysis revealed potential hsa‑miR‑19a/b‑3p binding sites in lncRNA H19 and ID2. Altogether, the results of the present study suggest that lncRNA H19 regulates the expression of ID2 through competitive binding to hsa‑miR‑19a and hsa‑miR‑19b, which may serve a role in AML cell proliferation.

TRAP1 is involved in BRAF regulation and downstream attenuation of ERK phosphorylation and cell-cycle progression: a novel target for BRAF-mutated colorectal tumors

Human BRAF-driven tumors are aggressive malignancies with poor clinical outcome and lack of sensitivity to therapies. TRAP1 is a HSP90 molecular chaperone deregulated in human tumors and responsible for specific features of cancer cells, i.e., protection from apoptosis, drug resistance, metabolic regulation, and protein quality control/ubiquitination. The hypothesis that TRAP1 plays a regulatory function on the BRAF pathway, arising from the observation that BRAF levels are decreased upon TRAP1 interference, was tested in human breast and colorectal carcinoma in vitro and in vivo. This study shows that TRAP1 is involved in the regulation of BRAF synthesis/ubiquitination, without affecting its stability. Indeed, BRAF synthesis is facilitated in a TRAP1-rich background, whereas increased ubiquitination occurs upon disruption of the TRAP1 network that correlates with decreased protein levels. Remarkably, BRAF downstream pathway is modulated by TRAP1 regulatory activity: indeed, TRAP1 silencing induces (i) ERK phosphorylation attenuation, (ii) cell-cycle inhibition with cell accumulation in G0-G1 and G2-M transitions, and (iii) extensive reprogramming of gene expression. Interestingly, a genome-wide profiling of TRAP1-knockdown cells identified cell growth and cell-cycle regulation as the most significant biofunctions controlled by the TRAP1 network. It is worth noting that TRAP1 regulation on BRAF is conserved in human colorectal carcinomas, with the two proteins being frequently coexpressed. Finally, the dual HSP90/TRAP1 inhibitor HSP990 showed activity against the TRAP1 network and high cytostatic potential in BRAF-mutated colorectal carcinoma cells. Therefore, this novel TRAP1 function represents an attractive therapeutic window to target dependency of BRAF-driven tumors on TRAP1 translational/quality control machinery.

Anti-inflammatory activity of ezetimibe by regulating NF-κB/MAPK pathway in THP-1 macrophages

Inflammation plays a crucial role in atherosclerosis. Monocytes/macrophages are involved in the inflammatory process during atherogenesis. Here, we performed daily gavage of ezetimibe in apolipoprotein E-deficient mice fed with a high-fat diet and found that ezetimibe administration decreased the level of C-reactive protein significantly. To investigate the potential molecular mechanism, we employed microarray analysis on the cultured macrophages treated with Chol:MβCD in the presence or absence of ezetimibe. We found that ezetimibe dramatically down-regulated the expression of the tumor necrosis factor-α (TNF-α) gene. Consistent with the microarray results, TNF-α protein levels were inhibited by ezetimibe. Moreover, ezetimibe suppressed the promoter activity of TNF-α but not TNF-α lacking the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) binding domain in THP-1 cells treated with phorbol myristate acetate and Chol:MβCD. Furthermore, treatment of THP-1 macrophages with ezetimibe resulted in the degradation of IκB and subsequently inhibited nuclear translocation of NF-κB and its transcriptional activity. Inhibition of the mitogen-activated protein kinase (MAPK) pathway using PD98059 attenuated the reduction effect of ezetimibe on the expression of NF-κB. Collectively, our results demonstrated that the anti-inflammatory properties of ezetimibe in THP-1 macrophages are, at least in part, through suppression of NF-κB activation via the MAPK pathway. These data provide direct evidence for the potential application of ezetimibe in the prevention and treatment of inflammatory diseases.

Upregulated H19 contributes to bladder cancer cell proliferation by regulating ID2 expression

Long noncoding RNAs have been shown to have important regulatory roles in cancer biology, and long noncoding RNA 19 (H19) is essential for human tumor growth. However, little is known about how abnormal expression of H19 contributes to bladder cancer cell proliferation. In this study, we first evaluated the expression of H19 in bladder cancer tissues by real-time PCR, and defined the biological functions. We found that H19 expression levels were remarkably increased in bladder cancer tissues as compared with adjacent normal control tissue, and forced expression of H19 promoted bladder cancer cell proliferation in vitro. Inhibitor of DNA binding/differentiation 2 (ID2) expression levels were upregulated in bladder cancer tissues and in bladder cancer cells. A significant positive correlation was observed between H19 levels and ID2 levels in vivo. We further demonstrated that overexpression of H19 resulted in a significant increase in the expression of ID2, whereas H19 knockdown decreased ID2 expression in vitro. Gain-of-function and loss-of-function studies demonstrated that upregulated H19 increased bladder cancer cell proliferation by increasing ID2 expression. In conclusion, upregulated H19 increases bladder cancer growth by regulating ID2 expression, and thus may be helpful in the development of effective treatment strategies for bladder cancer.

Effect of TRAF6 on the biological behavior of human lung adenocarcinoma cell

Tumor necrosis factor receptor-associated factor 6 (TRAF6) is a unique adaptor protein of the tumor necrosis factor receptor-associated factor family that mediates both tumor necrosis factor receptor and interleukin-1 receptor/Toll-like receptor signaling. A recent study showed that TRAF6 played an important role in tumorigenesis and invasion through activation of nuclear factor kappa B (NF-κB). However, the biological role of TRAF6 remains unknown in lung cancer up to now. To address the expression of TRAF6 in lung cancer cells, four lung cancer cell lines (A549, HCC827, NCI-H292, and 95-D) and human bronchial epithelial cells were used to detect the expression of TRAF6 protein by western blotting. Results indicated that TRAF6 displayed an upregulation in human lung cancer cell lines. To investigate the effects of TRAF6 on the biological behavior of human lung adenocarcinoma cell, we generated human lung adenocarcinoma A549 cell line in which TRAF6 was depleted. The results showed that downregulation of TRAF6 could decrease cell viability, suppress cell proliferation and invasion, and promote cell apoptosis. At the same time, we explored the effects of TRAF6 on the expression of the following proteins: phosphor-NF-κB (p-p65), cyclin D1, caspase-3, and matrix metalloproteinase 9 (MMP9). Downregulation of TRAF6 could decrease the expression of p-p65, cyclin D1, and MMP9 and increase the expression of caspase-3. All these results suggested that TRAF6 might be involved in the potentiation of growth, proliferation, and invasion of A549 cell line, as well as the inhibition of A549 cell apoptosis by the activation of NF-κB. To make a long story short, the overexpression of TRAF6 might be related to the tumorigenesis and invasion of lung cancer.