Inhibitor of differentiation 1 contributes to head and neck squamous cell carcinoma survival via the NF-kappaB/survivin and phosphoinositide 3-kinase/Akt signaling pathways

ID2 promotes tumor progression and metastasis in thyroid cancer

BACKGROUND

Inhibitor of DNA Binding 2 (ID2) plays a crucial role in tumor cell proliferation, invasion, metastasis, and stemness. Aberrant ID2 expression is associated with poor prognosis in various cancers. However, the specific function of ID2 in thyroid cancer remain unclear.

METHOD

The TCGA database were utilized to explore the clinical relevance of ID2 in cancer. GO, KEGG, and TIMER were employed to predict the potential roles of ID2 in cancer. Functional analysis, including CCK-8, colony formation, transwell, wound healing, and sphere formation experiments, were conducted to determine the biological functions of ID2 in human cancers. Western blot (WB), RT-qPCR, and immunohistochemical (IHC) analyses were used to investigate the relationship between ID2 and downstream targets.

RESULTS

Our study revealed significant overexpression of ID2 in various malignant tumor cells. Knocking ID2 significantly inhibited cancer cell proliferation and invasion, while overexpressing ID2 enhanced these capabilities. Additionally, ID2 mediates resistance of cancer cells to protein kinase B (or Akt) inhibitions. Further WB and IHC experiments indicated that ID2 promotes the phosphorylation activation of phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway, thereby upregulating the expression of downstream proliferation, epithelial-mesenchymal transition (EMT), and stemness-related markers.

CONCLUSION

We found that ID2 significantly promotes thyroid cancer cell proliferation, migration, EMT, and stemness through the PI3K/Akt pathway. Moreover, ID2 plays a crucial role in regulating cancer immune responses. It may serve as a potential biomarker for enhancing the efficacy of chemotherapy, targeted therapy, and immunotherapy against cancer.

The Effect of Tumor Resection and Radiotherapy on the Expression of Stem Cell Markers (CD44 and CD133) in Patients with Squamous Cell Carcinoma

Background: Head and Neck Squamous Cell Carcinomas (HNSCCs) are heterogeneous malignancies that comprise 90% of the head and neck cancers. HNSCCs originate from the mucosal lining epithelium of the upper aerodigestive tract. Cancer stem cells (CSCs) that generate HNSCCs with the CD44, CD133, and ALDH phenotype and are resistant to radiotherapy and chemotherapy. In the current, the quantitative alteration in CD44 and CD133 expression pre- and post-tumor resection and radiotherapy was evaluated in HNSCC patients. Moreover, the alterations in the expression of Bax, Bak, Bcl-2, ALDH, and PTEN genes were measured. Materials and Methods: Flow cytometry was performed to evaluate the alterations in CD44 and CD133 surface markers pre- and posttumor resection and radiotherapy. Quantitative real-time RT-PCR (qRT-PCR) was conducted to investigate the mRNA expression levels of Bax, Bak, Bcl-2, ALDH, and PTEN. Results: The results indicated that the cancer stem cell CD44 surface marker significantly decreased after tumor resection and radiotherapy in HNSCC cases, while the decrease was insignificant for CD133 marker expression. mRNA expression level of Bcl-2 and ALDH was increased, but Bax and Bak gene expressions were reduced significantly Conclusion: The results also indicated that the expression of CD44 significantly decreased after tumor resection and radiotherapy. The upregulation of mRNA level of Bcl-2 and ALDH, and the downregulation of Bax and Bak gene expression were noted in these cases when compared to the healthy control group.

Targeted therapy for head and neck cancer: signaling pathways and clinical studies

Head and neck cancer (HNC) is malignant, genetically complex and difficult to treat and is the sixth most frequent cancer, with tobacco, alcohol and human papillomavirus being major risk factors. Based on epigenetic data, HNC is remarkably heterogeneous, and treatment remains challenging. There is a lack of significant improvement in survival and quality of life in patients with HNC. Over half of HNC patients experience locoregional recurrence or distal metastasis despite the current multiple traditional therapeutic strategies and immunotherapy. In addition, resistance to chemotherapy, radiotherapy and some targeted therapies is common. Therefore, it is urgent to explore more effective and tolerable targeted therapies to improve the clinical outcomes of HNC patients. Recent targeted therapy studies have focused on identifying promising biomarkers and developing more effective targeted therapies. A well understanding of the pathogenesis of HNC contributes to learning more about its inner association, which provides novel insight into the development of small molecule inhibitors. In this review, we summarized the vital signaling pathways and discussed the current potential therapeutic targets against critical molecules in HNC, as well as presenting preclinical animal models and ongoing or completed clinical studies about targeted therapy, which may contribute to a more favorable prognosis of HNC. Targeted therapy in combination with other therapies and its limitations were also discussed.

Evolving landscape of PD-L2: bring new light to checkpoint immunotherapy

Immune checkpoint blockade therapy targeting programmed cell death protein 1 (PD-1) has revolutionized the landscape of multiple human cancer types, including head and neck squamous carcinoma (HNSCC). Programmed death ligand-2 (PD-L2), a PD-1 ligand, mediates cancer cell immune escape (or tolerance independent of PD-L1) and predicts poor prognosis of patients with HNSCC. Therefore, an in-depth understanding of the regulatory process of PD-L2 expression may stratify patients with HNSCC to benefit from anti-PD-1 immunotherapy. In this review, we summarised the PD-L2 expression and its immune-dependent and independent functions in HNSCC and other solid tumours. We focused on recent findings on the mechanisms that regulate PD-L2 at the genomic, transcriptional, post-transcriptional, translational, and post-translational levels, also in intercellular communication of tumour microenvironment (TME). We also discussed the prospects of using small molecular agents indirectly targeting PD-L2 in cancer therapy. These findings may provide a notable avenue in developing novel and effective PD-L2-targeted therapeutic strategies for immune combination therapy and uncovering biomarkers that improve the clinical efficacy of anti-PD-1 therapies.

The role of inflammation in cadmium nephrotoxicity: NF-κB comes into view

Kidney diseases are major health problem and understanding the underlined mechanisms that lead to kidney diseases are critical research points with a marked potential impact on health. Cadmium (Cd) is a heavy metal that occurs naturally and can be found in contaminated food. Kidneys are the most susceptible organ to heavy metal intoxication as it is the main route of waste excretion. The harmful effects of Cd were previously well proved. Cd induces inflammatory responses, oxidative injury, mitochondrial dysfunction and disturbs Ca²⁺ homeostasis. The nuclear factor-kappa B (NF-κB) is a cellular transcription factor that regulates inflammation and controls the expression of many inflammatory cytokines. Therefore, great therapeutic benefits can be attained from NF-κB inhibition. In this review we focused on certain compounds including cytochalasin D, mangiferin, N-acetylcysteine, pyrrolidine dithiocarbamate, roflumilast, rosmarinic acid, sildenafil, sinapic acid, telmisartan and wogonin and certain plants as Astragalus Polysaccharide, Ginkgo Biloba and Thymus serrulatus that potently inhibit NF-κB and effectively counteracted Cd-associated renal intoxication. In conclusion, the proposed NF-κB involvement in Cd-renal intoxication clarified the underlined inflammation associated with Cd-nephropathy and the beneficial effects of NF-κB inhibitors that make them the potential to substantially optimize treatment protocols for Cd-renal intoxication.

Neisseria sicca and Corynebacterium matruchotii inhibited oral squamous cell carcinomas by regulating genome stability

Periodontitis is a risk factor for the development of oral squamous cell carcinomas (OSCC). Both DNA damage response (DDR) and activation of inflammasomes induced by the microbiome might play important roles in the development of tumors, in relation to genome stability of tumor cells. Herein, we explored whether periodontitis negative-associated bacteria (Neisseria sicca and Corynebacterium matruchotii, namely called ‘PNB’), which were highly abundant in healthy populations, could inhibit OSCC by promoting genome stability. Firstly, a murine SCC-7 tumor-bearing model that colonized with PNB was designed and used in this study. Then, cyclin D1 was detected by immunohistochemistry. Levels of DDR, NLRP3 inflammasomes and pro-inflammatory cytokines in tumors were detected by RT-qPCR or Western blot. Immune cells in spleens were detected by immunohistochemistry or immunofluorescence. Finally, the anti-cancer activity of PNB was assessed in vitro using CCK-8 assays and flow cystometry. Compared with the control, PNB decreased tumor weights from 0.77 ± 0.26 g to 0.42 ± 0.15 g and downregulated the expression of Cyclin D1. PNB activated the DDR by up-regulating γ-H2AX, p-ATR, and p-CHK1. PNB activated NLRP3 inflammasome-mediated pyroptosis via increases of NLRP3, gasdermin D, and mRNA levels of apoptosis-associated speck-like protein, Caspase-1. PNB suppressed the inflammatory response by down-regulating mRNA levels of NF-κΒ and IL-6 in tumors as well as the populations of CD4+ T cells and CD206+ immune cells in spleens. PNB inhibited proliferation and promoted cell death of HSC-3 cells. In conclusion, Neisseria sicca and Corynebacterium matruchotii showed a ‘probiotic bacterial’ potential to inhibit OSCC by regulating genome stability.

lncRNA lnc-POP1-1 upregulated by VN1R5 promotes cisplatin resistance in head and neck squamous cell carcinoma through interaction with MCM5

Cisplatin resistance is a major therapeutic challenge in advanced head and neck squamous cell carcinoma (HNSCC). Here, we aimed to investigate the key signaling pathway for cisplatin resistance in HNSCC cells. Vomeronasal type-1 receptor 5 (VN1R5) was identified as a cisplatin resistance-related protein and was highly expressed in cisplatin-resistant HNSCC cells and tissues. The long noncoding RNA (lncRNA) lnc-POP1-1 was confirmed to be a downstream target induced by VN1R5. VN1R5 transcriptionally regulated lnc-POP1-1 expression by activating the specificity protein 1 (Sp1) transcription factor via the cyclic AMP (cAMP)/protein kinase A (PKA) pathway. VN1R5 promoted cisplatin resistance in HNSCC cells in a lnc-POP1-1-dependent manner. Mechanistically, lnc-POP1-1 bound to the minichromosome maintenance deficient 5 (MCM5) protein directly and decelerated MCM5 degradation by inhibiting ubiquitination of the MCM5 protein, which facilitated the repair of DNA damage caused by cisplatin. In summary, we identified the cisplatin resistance-related protein VN1R5 and its downstream target lnc-POP1-1. Upon upregulation by VN1R5, lnc-POP1-1 promotes DNA repair in HNSCC cells through interaction with MCM5 and deceleration of its degradation.

High-Risk Human Papillomavirus and Epstein-Barr Virus Coinfection: A Potential Role in Head and Neck Carcinogenesis

Simple Summary

A subset of carcinomas that arise in the head and neck region show a viral etiology. In fact, a subgroup of oropharyngeal cancers are caused by some types of human papillomavirus (HPV), so-called high-risk (HR)-HPVs, whereas undifferentiated nasopharyngeal carcinomas are etiologically related to Epstein–Barr virus (EBV). However, studies have reported the presence of both HR-HPV and EBV in some types of head and neck cancers. In this review, we discuss the potential contribution and role of HR-HPV/EBV coinfection in head and neck carcinogenesis, as well as the mechanisms that are potentially involved. In addition, HR-HPV/EBV interaction models are proposed.

Abstract

High-risk human papillomaviruses (HR-HPVs) and Epstein–Barr virus (EBV) are recognized oncogenic viruses involved in the development of a subset of head and neck cancers (HNCs). HR-HPVs are etiologically associated with a subset of oropharyngeal carcinomas (OPCs), whereas EBV is a recognized etiological agent of undifferentiated nasopharyngeal carcinomas (NPCs). In this review, we address epidemiological and mechanistic evidence regarding a potential cooperation between HR-HPV and EBV for HNC development. Considering that: (1) both HR-HPV and EBV infections require cofactors for carcinogenesis; and (2) both oropharyngeal and oral epithelium can be directly exposed to carcinogens, such as alcohol or tobacco smoke, we hypothesize possible interaction mechanisms. The epidemiological and experimental evidence suggests that HR-HPV/EBV cooperation for developing a subset of HNCs is plausible and warrants further investigation.

The PI3K/Akt/mTORC signaling axis in head and neck squamous cell carcinoma: Possibilities for therapeutic interventions either as single agents or in combination with conventional therapies

The latest advances in the sequencing methods in head and neck squamous cell carcinoma (HNSCC) tissues have revolutionized our understanding of the disease by taking off the veil from the most frequent genetic alterations in the components of the oncogenic pathways. Among all the identified alterations, aberrancies in the genes attributed to the phosphoinositide 3-kinases (PI3K) axis have attracted special attention as they were altered in more than 90% of the tissues isolated from HNSCC patients. In fact, the association between these aberrancies and the increased risk of cancer metastasis suggested this axis as an "Achilles Heel" of HNSCC, which may be therapeutically targeted. The results of the clinical trials investigating the therapeutic potential of the inhibitors targeting the components of the PI3K axis in the treatment of HNSCC patients, either alone or in a combined-modal strategy, opened a new chapter in the treatment strategy of this malignancy. The present study aimed to review the importance of the PI3K axis in the pathogenesis of HNSCC and also provide a piece of information about the breakthroughs and challenges of PI3K inhibitors in the therapeutic strategies of the disease.

Cigarette smoking promotes keratinocyte malignancy via generation of cancer stem-like cells

Objectives: Cigarette smoking is involved in the pathogenesis of head and neck squamous cell carcinoma (HNSCC). However, the underlying molecular mechanisms of cigarette smoking-induced HNSCC carcinogenesis are unclear and may involve cancer stem-like cell generation. We examined the effects of cigarette smoke condensate (CSC) on the formation of cancer stem-like cells, which are rich in octamer-binding transcription factor (OCT)-4, inhibitor of differentiation 1 (ID1), nuclear factor (NF)-κB, and B lymphoma Mo-MLV insertion region 1 homolog (BMI-1). Materials and Methods: We used in vitro, in vivo, and archival human HNSCC tissue analysis to evaluate the effects of CSC on cancer stem-like cell formation. Results: We found that CSC regulated OCT-4 expression, which subsequently regulated ID1 and NF-κB, at the promoter, mRNA, and protein levels in vitro. Furthermore, OCT-4 knockdown with siRNA reduced ID1 expression. ID1 and NF-κB synergistically increased the expression of BMI-1 and stimulated keratinocyte sphere generation. In vivo, ID1 and NF-κB acted together to generate malignant xenograft tumors, which were aggressive locally and systemically metastatic. Clinical data confirmed that ID1- and NF-κB-positive patients had poor clinical outcomes and 5-year disease-free survival. Conclusion: Our data suggest that smoking cigarettes promoted cancer stem-like cell generation in the head and neck area via the OCT-4/ID1/NF-κB/BMI-1 signaling pathway.

Role of inhibitor of differentiation 3 gene in cellular differentiation of human corneal stromal fibroblasts

Purpose

Inhibitor of differentiation (Id) proteins are helix-loop-helix (HLH) transcriptional repressors that modulate a range of developmental and cellular processes, including cell differentiation and cell cycle mobilization. The inhibitor of differentiation 3 (Id3) gene, a member of the Id gene family, governs the expression and progression of transforming growth factor beta (TGFβ)-mediated cell differentiation. In the face of mechanical, chemical, or surgical corneal insults, corneal keratocytes differentiate into myofibroblasts for wound repair. Excessive development or persistence or both of myofibroblasts after wound repair results in corneal haze that compromises corneal clarity and visual function. The objective of this study was to investigate whether Id3 overexpression in human corneal stromal fibroblasts governs TGFβ-driven cellular differentiation and inhibits keratocyte to myofibroblast transformation.

Methods

Primary human corneal stromal fibroblast (h-CSF) cultures were generated from donor human corneas. Human corneal myofibroblasts (h-CMFs) were produced by growing h-CSF in the presence of TGFβ1 under serum-free conditions. The Id3 gene was cloned into a mammalian expression vector (pcDNA3 mCherry LIC cloning vector), and the nucleotide sequence of the vector constructs was confirmed with sequencing as well as through restriction enzyme analysis. The Id3 mammalian overexpression vector was introduced into h-CSFs using a lipofectamine transfection kit. The expression of Id3 in selected clones was characterized with quantitative real-time PCR (qRT-PCR), immunocytochemistry, and western blotting. Phase contrast microscopy and trypan blue exclusion assays were used to evaluate the effects of the transfer of the Id3 gene on the hCSF phenotype and viability, respectively. To analyze the inhibitory effects of the Id3 gene transfer on TGFβ-induced formation of h-CMFs, expression of the mRNA and protein of the myofibroblast marker alpha smooth muscle actin (α-SMA) was examined with qRT-PCR, western blotting, and immunocytochemistry. Student t test, analysis of variance (ANOVA), and Bonferroni adjustment for repeated measures were used for statistical analysis.

Results

The results indicate that Id3 overexpression does not alter the cellular phenotype or viability of h-CSFs. Overexpression of the Id3 gene in h-CSF cells grown in the presence of TGFβ1 under serum-free conditions showed a statistically significant decrease (76.3±4.3%) in α-SMA expression (p<0.01) compared to the naked-vector transfected or non-transfected h-CSF cells. Id3-transfected, naked-vector transfected, and non-transfected h-CSF cells grown in the absence of TGFβ1 showed the expected low expression of α-SMA (0-5%). Furthermore, Id3 overexpression statistically significantly decreased TGFβ-induced mRNA levels of profibrogenic genes such as fibronectin, collagen type I, and collagen type IV (1.80±0.26-, 1.70±0.35- and 1.70±0.36-fold, respectively; p<0.05) that a play role in stromal matrix modulation and corneal wound healing. Results of the protein analysis with western blotting indicated that Id3 overexpression in h-CSF cells effectively slows TGFβ-driven differentiation and formation of h-CMFs. Results for subsequent overexpression studies showed that this process occurs through the regulation of E2A, a TATA box protein.

Conclusions

Id3 regulates TGFβ-driven differentiation of h-CSFs and formation of h-CMFs in vitro. Targeted Id3 gene delivery has potential to treat corneal fibrosis and reestablish corneal clarity in vivo.

Prognostic ability of DNA-binding protein inhibitor ID-1 expression in patients with oral squamous cell carcinoma

DNA-binding protein inhibitor ID-1 (ID-1) plays a vital role in the development of cancer. In the present study, ID-1 expression in oral squamous cell carcinoma (OSCC), and its association with prognosis were investigated in 128 patients with OSCC, treated at the Qilu Hospital of Shandong University and followed up for an additional 10 years. Immunohistochemical analysis was performed to detect ID-1 expression, and the association between ID-1 expression and recurrence, and estimated disease-specific survival (DSS) time were subsequently analyzed using the Mann-Whitney U test and the Kaplan-Meier method, respectively. In addition, the log-rank test was implemented to compare the survival curves and multivariate Cox proportional hazards analysis was performed to assess the prognostic value of ID-1. The results demonstrated that ID-1 was highly expressed in the majority of OSCC tissues investigated, and ID-1 expression was significantly higher in cases with recurrence of local tumors and lymph node metastasis. Furthermore, higher ID-1 expression levels were associated with a shorter DSS time. Taken together, the results of the present study suggest that ID-1 may serve as an independent prognostic factor to predict DSS time in patients with OSCC.

Basic fibroblast growth factor protects against influenza A virus-induced acute lung injury by recruiting neutrophils

Influenza virus (IAV) infection is a major cause of severe respiratory illness that affects almost every country in the world. IAV infections result in respiratory illness and even acute lung injury and death, but the underlying mechanisms responsible for IAV pathogenesis have not yet been fully elucidated. In this study, the basic fibroblast growth factor 2 (FGF2) level was markedly increased in H1N1 virus-infected humans and mice. FGF2, which is predominately derived from epithelial cells, recruits and activates neutrophils via the FGFR2-PI3K-AKT-NFκB signaling pathway. FGF2 depletion or knockout exacerbated influenza-associated disease by impairing neutrophil recruitment and activation. More importantly, administration of the recombinant FGF2 protein significantly alleviated the severity of IAV-induced lung injury and promoted the survival of IAV-infected mice. Based on the results from experiments in which neutrophils were depleted and adoptively transferred, FGF2 protected mice against IAV infection by recruiting neutrophils. Thus, FGF2 plays a critical role in preventing IAV-induced lung injury, and FGF2 is a promising potential therapeutic target during IAV infection.

Prostate cancer cells hyper-activate CXCR6 signaling by cleaving CXCL16 to overcome effect of docetaxel

Molecular reprogramming in response to chemotherapeutics leads to poor therapeutic outcomes for prostate cancer (PCa). In this study, we demonstrated that CXCR6-CXCL16 axis promotes DTX resistance and acts as a counter-defense mechanism. After CXCR6 activation, cell death in response to DTX was inhibited, and blocking of CXCR6 potentiated DTX cytotoxicity. Moreover, in response to DTX, PCa cells expressed higher CXCR6, CXCL16, and ADAM-10. Furthermore, ADAM-10-mediated release of CXCL16 hyper-activated CXCR6 signaling in response to DTX. Activation of CXCR6 resulted in increased GSK-3β, NF-κB, ERK1/2 phosphorylation, and survivin expression, which reduce DTX response. Finally, treatment of PCa cells with anti-CXCR6 monoclonal antibody synergistically or additively induced cell death with ∼1.5-4.5 fold reduction in the effective concentration of DTX. In sum, our data imply that co-targeting of CXCR6 would lead to therapeutic enhancement of DTX, leading to better clinical outcomes for PCa patients.

ID1 Is Critical for Tumorigenesis and Regulates Chemoresistance in Glioblastoma

Glioblastoma is the most common primary brain tumor in adults. While the introduction of temozolomide chemotherapy has increased long-term survivorship, treatment failure and rapid tumor recurrence remains universal. The transcriptional regulatory protein, inhibitor of DNA-binding-1 (ID1), is a key regulator of cell phenotype in cancer. We show that CRISPR-mediated knockout of ID1 in glioblastoma cells, breast adenocarcinoma cells, and melanoma cells dramatically reduced tumor progression in all three cancer systems through transcriptional downregulation of EGF, which resulted in decreased EGFR phosphorylation. Moreover, ID1-positive cells were enriched by chemotherapy and drove tumor recurrence in glioblastoma. Addition of the neuroleptic drug pimozide to inhibit ID1 expression enhanced the cytotoxic effects of temozolomide therapy on glioma cells and significantly prolonged time to tumor recurrence. Conclusively, these data suggest ID1 could be a promising therapeutic target in patients with glioblastoma. SIGNIFICANCE: These findings show that the transcriptional regulator ID1 is critical for glioblastoma initiation and chemoresistance and that inhibition of ID1 enhances the effect of temozolomide, delays tumor recurrence, and prolongs survival.

Genetic Factors Associated with a Poor Outcome in Head and Neck Cancer Patients Receiving Definitive Chemoradiotherapy

About half of advanced stage head and neck squamous cell carcinoma (HNSCC) patients can be cured by chemoradiotherapy. Patient outcome may be partially determined by the genetic alterations in HNSCC, rendering these alterations promising candidate prognostic factors and/or therapeutic targets. However, their relevance in patient outcome prognosis remains to be assessed in patients that receive standard-of-care chemoradiotherapy. We therefore tested whether frequent genetic alterations were associated with progression free survival (PFS) in advanced stage HNSCC patients who were uniformly treated with definitive platinum-based chemoradiotherapy. To this end, we performed targeted DNA sequencing on frozen pre-treatment tumor biopsy material from 77 patients with advanced stage oro- and hypopharyngeal carcinoma. This provided somatic point mutation and copy number aberration data of 556 genes. The most frequently mutated genes, TP53 (62%), CCND1 (51%), CDKN2A (30%) and PIK3CA (21%), were not associated with PFS. However, co-occurring CCND1 and CDKN2A mutations were associated with short PFS (HR 2.24, p = 0.028) in HPV-negative tumors. Furthermore, tumor mutational burden (sum of somatic point mutations) showed a trend towards decreased PFS (HR 1.9, p = 0.089), and chromosomal instability (CIN) was associated with shorter PFS (HR 2.3, p = 0.023), independent of HPV status. Our results show that tumor mutational burden, CIN markers, and co-occurring CCND1 and CDKN2A mutations are associated with chemoradiotherapy outcomes in advanced stage oro- and hypopharyngeal HNSCC patients, thereby highlighting their prognostic potential. Given their poor prognosis association and link to biological targets, they may also identify patients for novel targeted therapies and immunotherapies.

Inhibitor of DNA binding proteins: implications in human cancer progression and metastasis

Inhibitor of DNA binding (ID) proteins are a class of helix-loop-helix (HLH) transcription regulatory factors that act as dominant-negative antagonists of other basic HLH proteins through the formation of non-functional heterodimers. These proteins have been shown to play critical roles in a wide range of tumor-associated processes, including cell differentiation, cell cycle progression, migration and invasion, epithelial-mesenchymal transition, angiogenesis, stemness, chemoresistance, tumorigenesis, and metastasis. The aberrant expression of ID proteins has not only been detected in many types of human cancers, but is also associated with advanced tumor stages and poor clinical outcome. In this review, we provide an overview of the key biological functions of ID proteins including affiliated signaling pathways. We also describe the regulation of ID proteins in cancer progression and metastasis, and elaborate on expression profiles in cancer and the implications for prognosis. Lastly, we outline strategies for the therapeutic targeting of ID proteins as a promising and effective approach for anticancer therapy.

Dioxonaphthoimidazoliums AB1 and YM155 disrupt phosphorylation of p50 in the NF-κB pathway

The NF-κB pathway is overexpressed in non-small cell lung cancers (NSCLC) and contributes to the poor prognosis and high mortality characterizing this malignancy. Silencing the p50 and p65 NF-κB subunits in the NSCLC H1299 cell line led to profound loss in cell viability and downregulated anti-apoptotic proteins survivin and Mcl1. We also showed that a survivin suppressant, the dioxonaphthoimidazolium YM155, and its structural analog AB1 arrested the growth of H1299 cells at nanomolar concentrations. Both compounds were apoptogenic and suppressed survivin and other anti-apoptotic proteins (Mcl1, Bcl-2, Bcl-xl) in a dose- and/or time-dependent manner. YM155 and AB1 did not affect the expression of key proteins (IκBα, p65, p50) involved in NF-κB signaling. Stable IκBα levels suggest that the NF-κB/IκB complex and proteins upstream of IκBα, were not targeted. Neither did the compounds intercept the nuclear translocation of the p50 and p65 subunits. On the other hand, YM155 and AB1 suppressed the phosphorylation of the p50 subunit at Ser337 which is critical in promoting the binding of NF-κB dimers to DNA. Both compounds duly impeded the binding of NF-κB dimers to DNA and attenuated transcriptional activity of luciferase-transfected HEK293 cells controlled by NF-κB response elements. We propose that the “silencing” the NF-κB pathway effected by these compounds contributed to their potent apoptogenic effects on H1299. Notwithstanding, the mechanism(s) involved in their ability to abolish phosphorylation of p50 remains to be elucidated. Taken together, these results disclose a novel facet of functionalized dioxonaphthoimidazoliums that could account for their potent cell killing property.

The Role of p16INK4a Pathway in Human Epidermal Stem Cell Self-Renewal, Aging and Cancer

The epidermis is a self-renewing tissue. The balance between proliferation and differentiation processes is tightly regulated to ensure the maintenance of the stem cell (SC) population in the epidermis during life. Aging and cancer may be considered related endpoints of accumulating damages within epidermal self-renewing compartment. p16^INK4a is a potent inhibitor of the G1/S-phase transition of the cell cycle. p16^INK4a governs the processes of SC self-renewal in several tissues and its deregulation may result in aging or tumor development. Keratinocytes are equipped with several epigenetic enzymes and transcription factors that shape the gene expression signatures of different epidermal layers and allow dynamic and coordinated expression changes to finely balance keratinocyte self-renewal and differentiation. These factors converge their activity in the basal layer to repress p16^INK4a expression, protecting cells from senescence, and preserving epidermal homeostasis and regeneration. Several stress stimuli may activate p16^INK4a expression that orchestrates cell cycle exit and senescence response. In the present review, we discuss the role of p16^INK4a regulators in human epidermal SC self-renewal, aging and cancer.

Action of YM155 on clear cell renal cell carcinoma does not depend on survivin expression levels

The dioxonapthoimidazolium YM155 is a survivin suppressant which has been investigated as an anticancer agent in clinical trials. Here, we investigated its growth inhibitory properties on a panel of immortalized and patient derived renal cell carcinoma (RCC) cell lines which were either deficient in the tumour suppressor von Hippel-Lindau (VHL) protein or possessed a functional copy. Neither the VHL status nor the survivin expression levels of these cell lines influenced their susceptibility to growth inhibition by YM155. Of the various RCC lines, the papillary subtype was more resistant to YM155, suggesting that the therapeutic efficacy of YM155 may be restricted to clear cell subtypes. YM155 was equally potent in cells (RCC786.0) in which survivin expression had been stably silenced or overexpressed, implicating a limited reliance on survivin in the mode of action of YM155. A follow-up in-vitro high throughput RNA microarray identified possible targets of YM155 apart from survivin. Selected genes (ID1, FOXO1, CYLD) that were differentially expressed in YM155-sensitive RCC cells and relevant to RCC pathology were validated with real-time PCR and western immunoblotting analyses. Thus, there is corroboratory evidence that the growth inhibitory activity of YM155 in RCC cell lines is not exclusively mediated by its suppression of survivin. In view of the growing importance of combination therapy in oncology, we showed that a combination of YM155 and sorafenib at ½ x IC50 concentrations was synergistic on RCC786.0 cells. However, when tested intraperitoneally on a murine xenograft model derived from a nephrectomised patient with clear cell RCC, a combination of suboptimal doses of both drugs failed to arrest tumour progression. The absence of synergy in vivo highlighted the need to further optimize the dosing schedules of YM155 and sorafenib, as well as their routes of administration. It also implied that the expression of other oncogenic proteins which YM155 may target is either low or absent in this clear cell RCC.

High expression of ID family and IGJ genes signature as predictor of low induction treatment response and worst survival in adult Hispanic patients with B-acute lymphoblastic leukemia

Background

B-Acute lymphoblastic leukemia (B-ALL) represents a hematologic malignancy with poor clinical outcome and low survival rates in adult patients. Remission rates in Hispanic population are almost 30 % lower and Overall Survival (OS) nearly two years inferior than those reported in other ethnic groups. Only 61 % of Colombian adult patients with ALL achieve complete remission (CR), median overall survival is 11.3 months and event-free survival (EFS) is 7.34 months. Identification of prognostic factors is crucial for the application of proper treatment strategies and subsequently for successful outcome. Our goal was to identify a gene expression signature that might correlate with response to therapy and evaluate the utility of these as prognostic tool in hispanic patients.

Methods

We included 43 adult patients newly diagnosed with B-ALL. We used microarray analysis in order to identify genes that distinguish poor from good response to treatment using differential gene expression analysis. The expression profile was validated by real-time PCR (RT-PCT).

Results

We identified 442 differentially expressed genes between responders and non-responders to induction treatment. Hierarchical analysis according to the expression of a 7-gene signature revealed 2 subsets of patients that differed in their clinical characteristics and outcome.

Conclusions

Our study suggests that response to induction treatment and clinical outcome of Hispanic patients can be predicted from the onset of the disease and that gene expression profiles can be used to stratify patient risk adequately and accurately. The present study represents the first that shows the gene expression profiling of B-ALL Colombian adults and its relevance for stratification in the early course of disease.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-016-0333-z) contains supplementary material, which is available to authorized users.

Mitochondria can orchestrate sex differences in cell fate of vascular smooth muscle cells from rats

Background

In basal conditions, vascular smooth muscle cells freshly isolated from aortas of male and female rats display marked sex differences in terms of redox balance and susceptibility to ultraviolet radiation-induced cell death. In particular, in the same experimental conditions, cells from male rats are more susceptible to oxidative stress and underwent apoptosis, while cells from female rats underwent premature senescence. In the present work, the mechanism involved in cell fate after ultraviolet radiation exposure is investigated.

Methods

Vascular smooth muscle cells, isolated from the descending aortas of both female and male Sprague–Dawley young rats, were exposed to a single sub-cytotoxic dose of ultraviolet radiation (200 mJ/cm²). The distribution and the expression of molecules involved in cell survival and mitochondrial physiology were evaluated by static and flow cytometry using commercial kits and antibodies. Statistical analyses were performed by using Student’s t test and two-way ANOVA.

Results

After exposure to ultraviolet radiation, an upregulation of survival proteins such as Bclx_L, survivin and the presence in the nucleus of NF-κB were found in cells from females. Conversely, pro-apoptotic proteins such as Bax, caspase-3, and caspase-9 as well as loss of mitochondrial membrane potential were found in cells from male rats.

Conclusions

Our results suggest that (i) mitochondria, being producers of ROS, can orchestrate sex differences in cell fate of VSMC and (ii) mitochondrial dysfunction may be a significant mechanism by which cardiovascular risk factors lead to the formation of vascular lesions in a sex-specific way.

Inhibition of phospholipaseD2 increases hypoxia-induced human colon cancer cell apoptosis through inactivating of the PI3K/AKT signaling pathway

Hypoxia is a common feature of solid tumor, and is a direct stress that triggers apoptosis in many human cell types. As one of solid cancer, hypoxia exists in the whole course of colon cancer occurrence and progression. Our previous studies shown that hypoxia induce high expression of phospholipase D2 (PLD2) and survivin in colon cancer cells. However, the correlation between PLD2 and survivin in hypoxic colon cancer cells remains unknown. In this study, we observed significantly elevated PLD2 and survivin expression levels in colon cancer tissues and cells. This is a positive correlation between of them, and co-expression of PLD2 and survivin has a positive correlation with the clinicpatholic features including tumor size, TNM stage, and lymph node metastasis. We also found that hypoxia induced the activity of PLD increased significant mainly caused by PLD2 in colon cancer cells. However, inhibition the activity of PLD2 induced by hypoxia promotes the apoptosis of human colon cancer cells, as well as decreased the expression of apoptosis markers including survivin and bcl2. Moreover, the pharmacological inhibition of PI3K/AKT supported the hypothesis that promotes the apoptosis of hypoxic colon cancer cells by PLD2 activity inhibition may through inactivation of the PI3K/AKT signaling pathway. Furthermore, interference the PLD2 gene expression leaded to the apoptosis of hypoxic colon cancer cells increased and also decreased the expression level of survivin and bcl2 may through inactivation of PI3K/AKT signaling pathway. These results indicated that PLD2 play antiapoptotic role in colon cancer under hypoxic conditions, inhibition of the activity, or interference of PLD2 gene expression will benefit for the treatment of colon cancer patients.

High Id1 expression, a generally negative prognostic factor, paradoxically predicts a favorable prognosis for adjuvant paclitaxel plus cisplatin therapy in surgically treated lung cancer patients

Adjuvant chemotherapy is commonly given to surgically treated non-small-cell lung cancer (NSCLC) patients. However, the prerequisite for chemotherapy needs to be scrutinized in order to maximize the benefits to patients. In this study, we observed that NSCLC cells with high Id1 protein expression were vulnerable to the treatment of paclitaxel and cisplatin. In addition, paclitaxel and cisplatin caused Id1 protein degradation through ubiquitination. In the nude mice xenograft model, the tumor growth was reduced to a large degree in the Id1-overexpressing group upon treatment with paclitaxel and cisplatin. Furthermore, immunohistochemical staining for Id1 followed by Kaplan-Meier survival analysis showed that surgically treated NSCLC patients with high Id1 expression in primary tumor tissues had better disease-free and overall survivals after adjuvant paclitaxel and cisplatin chemotherapy. In summary, our current data suggest that Id1, a generally negative prognostic factor, predicts a favorable prognosis in the case of surgically treated NSCLC patients receiving the definitive adjuvant chemotherapy. The distinct role of Id1 reported in this study may arise from the phenomenon of Id1 dependence of NSCLC cells for survival, which renders the cancer cells additionally susceptive to the adjuvant chemotherapy with paclitaxel and cisplatin.

GCIP functions as a tumor suppressor in non-small cell lung cancer by suppressing Id1-mediated tumor promotion

Grap2 and cyclin D1 interacting protein (GCIP) has been recognized as a putative tumor suppressor, but the molecular mechanisms underlying its anti-tumor properties remain undefined. Here, we report that GCIP is frequently downregulated in non-small cell lung cancer (NSCLC) tissues. Binding assays indicated that inhibitor of DNA binding/differentiation 1 (Id1) interacts with GCIP in the nucleus. Ectopic GCIP expression in the highly invasive NSCLC cell line, H1299, inhibited proliferation, colony formation, invasion and migration, and increased susceptibility to anticancer drugs. Conversely, silencing GCIP expression in the minimally invasive NSCLS cell line, A549, increased proliferation, colony formation, invasion, and migration in vitro, and increased survival and resistance to anticancer drugs. GCIP also suppresses tumorigenicity of NSCLC cells in vivo and GCIP suppresses NSCLC progression is mediated in part by interfering with Id1 signaling, which was confirmed in conditionally induced stable cell lines. In addition, GCIP downregulates the expression of Id1, and GCIP and Id1 are inversely expressed in NSCLC cell lines and specimens. Taken together, these results suggest that GCIP is a potential tumor suppressor in NSCLC and that suppression of Id1-mediated oncogenic properties may be a key mechanism by which GCIP can potently suppress NSCLC tumor progression.

Gene expression profile analysis of SUDHL6 cells with siRNA-mediated BCL11A downregulation

Our previous study has shown that downregulation of B-cell chronic lymphocytic leukemia (CLL)/lymphoma11A (BCL11A) gene by small interfering RNA (siRNA) resulted in the growth inhibition and apoptosis of B cell lymphoma cell line SUDHL6. To gain further insight into the molecular mechanisms of this process and identify the differentially expressed genes in SUDHL6 cells after BCL11A downregulation, the global gene expression profile was identified and analyzed using the Affymetrix HG-U133 Plus 2.0 array. Twenty-one differentially expressed genes were validated and analyzed from the BCL11A siRNA-treated SUDHL6 cells. There was a significant dysregulation in the global gene expression of the BCL11A-suppressed SUDHL6 cells. There were 1903 genes differentially expressed with >2-fold changes between the BCL11A siRNA- and negative control-transfected cells. Of these, there were 916 upregulated genes and 987 downregulated genes. The differential genes are involved in various molecular functions and signaling pathways. QRT-PCR validation of the selected differentially expressed genes demonstrated there was a good correlation with the microarray analysis. There was a significant deregulation of expression in the apoptosis-related genes such as BCL-2, BCL2L11 and involved in TGFβ, MAPK, WNT signaling pathways after BCL11A was downregulated in SUDHL6 cells. Our results show that the suppression of BCL11A by RNA interference altered gene expression profile of SUDHL6 cells. The apoptosis-related genes BCL-2, BCL2L11 and the gene alterations in TGFβ, MAPK, WNT signaling pathways might be important in BCL11A siRNA-induced apoptosis of SUDHL6 cells, suggesting BCL11A is involved in gene networks associated with apoptosis.

Activation of nuclear factor κB pathway and downstream targets survivin and livin by SHARPIN contributes to the progression and metastasis of prostate cancer

BACKGROUND

Nuclear factor κB (NFκB) signaling is strongly associated with tumor progression, and studies have shown that SHANK-associated RH domain interacting protein (SHARPIN) is crucial for NFκB pathway activation. However, the expression and functions of SHARPIN in prostate cancer (PCa) have not yet been defined.

METHODS

The expression of SHARPIN in PCa cell lines and tissues was evaluated with western blotting, quantitative real-time polymerase chain reaction, and immunohistochemistry. After SHARPIN was silenced in the PCa cell lines, western blots were used to confirm that SHARPIN physically associated with components of the NFκB pathway and the downstream targets (survivin and livin). The functions of SHARPIN in cell proliferation, migration, and invasion in vitro were measured with 5-(3-carboxymethoxyphenyl)-2-(4,5-dimenthylthiazoly)-3-(4-sulfophenyl)tetrazolium, inner salt (MTS), Transwell, and invasion assays, respectively. Flow cytometry was employed to evaluate cell apoptosis. Furthermore, tumorigenesis in vivo was examined with tumorigenicity assays.

RESULTS

SHARPIN expression was upregulated in PCa cell lines and tissues. The knockdown of SHARPIN or incubation with Bay 11-7082 (an NFκB inhibitor) led to dramatically decreased levels of phosphorylated IκBα and phosphorylated p65 in comparison with the control group. Downregulation of survivin and livin due to SHARPIN inhibition was attributable to transcriptional repression (P < .05). Decreases in cell viability, migration, invasion, and survival with a higher sensitivity to docetaxel in vitro and with repressed tumorigenesis in vivo were observed upon SHARPIN silencing, and this was consistent with the results from inhibition of the NFκB pathway and its downstream targets.

CONCLUSION

The current study demonstrates that overexpression of SHARPIN promotes activation of the NFκB pathway and downstream targets survivin and livin, which potentially contributes to PCa development.

ID proteins regulate diverse aspects of cancer progression and provide novel therapeutic opportunities

The inhibitor of differentiation (ID) proteins are helix-loop-helix transcriptional repressors with established roles in stem cell self-renewal, lineage commitment, and niche interactions. While deregulated expression of ID proteins in cancer was identified more than a decade ago, emerging evidence has revealed a central role for ID proteins in neoplastic progression of multiple tumor types that often mirrors their function in physiological stem and progenitor cells. ID proteins are required for the maintenance of cancer stem cells, self-renewal, and proliferation in a range of malignancies. Furthermore, ID proteins promote metastatic dissemination through their role in remodeling the tumor microenvironment and by promoting tumor-associated endothelial progenitor cell proliferation and mobilization. Here, we discuss the latest findings in this area and the clinical opportunities that they provide.

Id1 and NF-κB promote the generation of CD133+ and BMI-1+ keratinocytes and the growth of xenograft tumors in mice

Id1 and NF-κB are highly expressed in oral squamous cell carcinoma (OSCC). Whether they have a synergistic role in the carcinogenesis of OSCC is unclear. The current study was designed to demonstrate the synergy of both Id1 and NF-κB in the underlying disease mechanisms of OSCC using in vitro and in vivo animal models. Id1 and NF-κB strengthened the expression of both CD133 and BMI-1 in OSCC cell cultures. CD133(+) and BMI-1(+) keratinocytes from OSCC tissues and cell cultures initiated the growth of xenograft tumors in SCID/Beige mice. Id1 and NF-κB regulate the expression of CD133 and BMI-1 in an additive or synergistic manner in OSCC, which is associated with the generation of naïve and self-renewable keratinocytes and initiate the growth of xenograft tumors in vivo.

The ID proteins: master regulators of cancer stem cells and tumour aggressiveness

Inhibitor of DNA binding (ID) proteins are transcriptional regulators that control the timing of cell fate determination and differentiation in stem and progenitor cells during normal development and adult life. ID genes are frequently deregulated in many types of human neoplasms, and they endow cancer cells with biological features that are hijacked from normal stem cells. The ability of ID proteins to function as central 'hubs' for the coordination of multiple cancer hallmarks has established these transcriptional regulators as therapeutic targets and biomarkers in specific types of human tumours.

Id proteins: small molecules, mighty regulators

The family of inhibitor of differentiation (Id) proteins is a group of evolutionarily conserved molecules, which play important regulatory roles in organisms ranging from Drosophila to humans. Id proteins are small polypeptides harboring a helix-loop-helix (HLH) motif, which are best known to mediate dimerization with other basic HLH proteins, primarily E proteins. Because Id proteins do not possess the basic amino acids adjacent to the HLH motif necessary for DNA binding, Id proteins inhibit the function of E protein homodimers, as well as heterodimers between E proteins and tissue-specific bHLH proteins. However, Id proteins have also been shown to have E protein-independent functions. The Id genes are broadly but differentially expressed in a variety of cell types. Transcription of the Id genes is controlled by transcription factors such as C/EBPβ and Egr as well as by signaling pathways triggered by different stimuli, which include bone morphogenic proteins, cytokines, and ligands of T cell receptors. In general, Id proteins are capable of inhibiting the differentiation of progenitors of different cell types, promoting cell-cycle progression, delaying cellular senescence, and facilitating cell migration. These properties of Id proteins enable them to play significant roles in stem cell maintenance, vasculogenesis, tumorigenesis and metastasis, the development of the immune system, and energy metabolism. In this review, we intend to highlight the current understanding of the function of Id proteins and discuss gaps in our knowledge about the mechanisms whereby Id proteins exert their diverse effects in multiple cellular processes.

Survivin-induced abnormal ploidy contributes to cystic kidney and aneurysm formation

BACKGROUND

Cystic kidneys and vascular aneurysms are clinical manifestations seen in patients with polycystic kidney disease, a cilia-associated pathology (ciliopathy). Survivin overexpression is associated with cancer, but the clinical pathology associated with survivin downregulation or knockout has never been studied before. The present studies aim to examine whether and how cilia function (Pkd1 or Pkd2) and structure (Tg737) play a role in cystic kidney and aneurysm through survivin downregulation.

METHODS AND RESULTS

Cysts and aneurysms from polycystic kidney disease patients, Pkd mouse, and zebrafish models are characterized by chromosome instability and low survivin expression. This triggers cytokinesis defects and formation of nuclear polyploidy or aneuploidy. In vivo conditional mouse and zebrafish models confirm that survivin gene deletion in the kidneys results in a cystic phenotype. As in hypertensive Pkd1, Pkd2, and Tg737 models, aneurysm formation can also be induced in vascular-specific normotensive survivin mice. Survivin knockout also contributes to abnormal oriented cell division in both kidney and vasculature. Furthermore, survivin expression and ciliary localization are regulated by flow-induced cilia activation through protein kinase C, Akt and nuclear factor-κB. Circumventing ciliary function by re-expressing survivin can rescue polycystic kidney disease phenotypes.

CONCLUSIONS

For the first time, our studies offer a unifying mechanism that explains both renal and vascular phenotypes in polycystic kidney disease. Although primary cilia dysfunction accounts for aneurysm formation and hypertension, hypertension itself does not cause aneurysm. Furthermore, aneurysm formation and cyst formation share a common cellular and molecular pathway involving cilia function or structure, survivin expression, cytokinesis, cell ploidy, symmetrical cell division, and tissue architecture orientation.

Granulocyte macrophage colony-stimulating factor shows anti-apoptotic activity via the PI3K-NF-κB-HIF-1α-survivin pathway in mouse neural progenitor cells

Granulocyte macrophage-colony stimulating factor (GM-CSF) is a hematopoietic cytokine that plays a crucial role in regulating the proliferation, differentiation, and survival of hematopoietic cells. Recent studies have shown that GM-CSF also has anti-apoptotic effects and regulates the expression of anti-apoptotic genes including Bcl-2 family proteins in neuronal cells in vitro and in vivo. However, the mechanism underlying the anti-apoptotic function of GM-CSF is not well understood. In the present work, we examined the role of phosphoinositide 3-kinase (PI3K)-AKT signal pathway in the anti-apoptotic activity of GM-CSF in mouse neural progenitor cells (NPCs). In terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, the anti-apoptotic effect of GM-CSF (apoptotic population of approximately 8.17 %) on staurosporine-induced apoptosis of NPCs (31.09 %) was significantly blocked by LY294002, an inhibitor of PI3K signal (24.04 %). We found that the PI3K-AKT signal pathway induced by GM-CSF treatment activated nuclear factor κB (NF-κB) and increased the expression of hypoxia-inducible factor 1α (HIF-1α) in normoxic conditions. Analyses using specific small interfering RNAs (siRNAs) showed that NF-κB was an upstream molecule of HIF-1α and activated its expression at the mRNA level. Further analyses using the siRNAs and chromatin immunoprecipitation (ChIP) showed that HIF-1α was responsible for the induced expression of survivin, a member of the inhibitor of apoptosis proteins (IAPs). Each of the specific siRNAs for NF-κB, HIF-1α, and survivin inhibited significantly the anti-apoptotic activity of GM-CSF on the staurosporine-induced apoptosis in NPCs in TUNEL assays. The results of this study showed the downstream signals and mechanism of PI3K/AKT-mediated anti-apoptotic activity of GM-CSF in NPCs, particularly revealing the role of the NF-κB-HIF-1α-survivin cascade.

Id1 enhances human ovarian cancer endothelial progenitor cell angiogenesis via PI3K/Akt and NF-κB/MMP-2 signaling pathways

BACKGROUND

Endothelial progenitor cells (EPCs) contribute to tumor angiogenesis and growth. We previously reported that over-expression of an inhibitor of DNA binding/differentiation 1 (Id1) in EPCs can enhance EPC proliferation, migration, and adhesion. In this study, we investigated the role of Id1 in EPC angiogenesis in patients with ovarian cancer and the underlying signaling pathway.

METHODS

Circulating EPCs from 22 patients with ovarian cancer and 15 healthy control subjects were cultured. Id1 and matrix metalloproteinase-2 (MMP-2) expression were analyzed by real-time reverse transcription-polymerase chain reaction (RT-PCR) and western blot. EPC angiogenesis was detected by tube formation assays. Double-stranded DNA containing the interference sequences was synthesized according to the structure of a pGCSIL-GFP viral vector and then inserted into a linearized vector. Positive clones were identified as lentiviral vectors that expressed human Id1 short hairpin RNA (shRNA).

RESULTS

Id1 and MMP-2 expression were increased in EPCs freshly isolated from ovarian cancer patients compared to those obtained from healthy subjects. shRNA-mediated Id1 down-regulation substantially reduced EPC angiogenesis and MMP-2 expression. Importantly, transfection of EPCs with Id1 in vitro induced phosphorylation of Akt (p-Akt) via phosphoinositide 3-kinase and increased the expression of MMP-2 via NF-κB. Blockage of both pathways by specific inhibitors (LY294002 and PDTC, respectively) abrogated Id1-enhanced EPC angiogenesis.

CONCLUSIONS

Id1 can enhance EPC angiogenesis in ovarian cancer, which is mainly mediated by the PI3K/Akt and NF-κB/MMP-2 signaling pathways. Id1 and its downstream effectors are potential targets for treatment of ovarian cancer because of their contribution to angiogenesis.

A survivin-associated adaptive response in radiation therapy

Adaptive responses can be induced in cells by very low doses of ionizing radiation resulting in an enhanced resistance to much larger exposures. The inhibitor of apoptosis protein, survivin, has been implicated in many adaptive responses to cellular stress. Computerized axial tomography used in image-guided radiotherapy to position and monitor tumor response uses very low radiation doses ranging from 0.5 to 100 mGy. We investigated the ability of these very low radiation doses administered along with two 2 Gy doses separated by 24 hours, a standard conventional radiotherapy dosing schedule, to initiate adaptive responses resulting in the elevation of radiation resistance in exposed cells. Human colon carcinoma (RKO36), mouse sarcoma (SA-NH), along with transformed mouse embryo fibroblasts, wild type or cells lacking functional tumor necrosis factor receptors 1 and 2 were used to assess their relative ability to express an adaptive response when grown either to confluence in vitro or as tumors in the flank of C57BL/6 mice. The survival of each of these cells was elevated from 5% to 20% (P ≤ 0.05) as compared to cells not receiving a 100 mGy or lesser dose. In addition, the cells exposed to 100 mGy exhibited elevations in survivin levels, reductions in apoptosis frequencies, and loss of an adaptive response if transfected with survivin siRNA. This survivin-mediated adaptive response has the potential for affecting outcomes if regularly induced throughout a course of image guided radiation therapy.

IL-6 expression regulates tumorigenicity and correlates with prognosis in bladder cancer

Identification of potential tumor markers will help stratify and identify a tumor's malignant potential and its response to specific therapies. IL-6 has been reported to be a predictor in various cancers. Therefore, the present study was performed to highlight the role of IL-6 in improving treatment and determining prognosis of bladder cancer. The human bladder cancer cell lines HT1376 and HT1197 were selected for cell and animal experiments, in which biological changes after experimental manipulation of IL-6 were explored, including tumor behavior and related signaling in bladder cancer. In addition, clinical specimens from 85 patients with muscle-invasive, and 50 with non-muscle invasive bladder cancers were selected for immunohistochemical staining to evaluate the predictive capacity of IL-6 in relation to clinical outcome. The data revealed that IL-6 was overexpressed in the bladder cancer specimens compared with non-malignant tissues at both mRNA and protein levels. Positive staining of IL-6 was significantly correlated with higher clinical stage, higher recurrence rate after curative treatment, and reduced survival rate. Tumor growth and invasive capability were attenuated when IL-6 was blocked. The underlying changes included decreased cell proliferation, less epithelial-mesenchymal transition (EMT), decreased DNA methyltransferase 1 expression and attenuated angiogenesis. In conclusion, our findings showed that IL-6 could be a significant predictor for clinical stage and prognosis of bladder cancer. Moreover, targeting IL-6 may be a promising strategy for treating bladder cancer.

Bone morphogenetic protein type I receptor antagonists decrease growth and induce cell death of lung cancer cell lines

Bone morphogenetic proteins (BMPs) are highly conserved morphogens that are essential for normal development. BMP-2 is highly expressed in the majority of non-small cell lung carcinomas (NSCLC) but not in normal lung tissue or benign lung tumors. The effects of the BMP signaling cascade on the growth and survival of cancer cells is poorly understood. We show that BMP signaling is basally active in lung cancer cell lines, which can be effectively inhibited with selective antagonists of the BMP type I receptors. Lung cancer cell lines express alk2, alk3, and alk6 and inhibition of a single BMP receptor was not sufficient to decrease signaling. Inhibition of more than one type I receptor was required to decrease BMP signaling in lung cancer cell lines. BMP receptor antagonists and silencing of BMP type I receptors with siRNA induced cell death, inhibited cell growth, and caused a significant decrease in the expression of inhibitor of differentiation (Id1, Id2, and Id3) family members, which are known to regulate cell growth and survival in many types of cancers. BMP receptor antagonists also decreased clonogenic cell growth. Knockdown of Id3 significantly decreased cell growth and induced cell death of lung cancer cells. H1299 cells stably overexpressing Id3 were resistant to growth suppression and induction of cell death induced by the BMP antagonist DMH2. These studies suggest that BMP signaling promotes cell growth and survival of lung cancer cells, which is mediated through its regulation of Id family members. Selective antagonists of the BMP type I receptors represents a potential means to pharmacologically treat NSCLC and other carcinomas with an activated BMP signaling cascade.

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

Squamous cell carcinoma (SCC) is a significant cause of cancer morbidity and mortality worldwide, with an incidence of up to 166 cases per 100 000 population. It arises in the skin, upper aerodigestive tract, lung, and cervix and affects more than 200 000 Americans each year. We report here that a microarray experiment comparing 41 SCC and 13 normal tissue specimens showed that Id2, a gene that controls the cell cycle, was significantly up-regulated in SCC. Enforced expression of Id2 in vitro stimulated the proliferation of SCC cells and up-regulated the transcription of nuclear factor kappa B (NF-κB) and cyclin D1. Enhancement of the NF-κB activity with p65 significantly increased the cell proliferation and the transcription of cyclin D1, whereas inhibition of the NF-κB activity with I kappa B alpha mutant (IκBα M) and pyrroline dithiocarbamate (PDTC) abrogated cell proliferation and transcription of cyclin D1. Furthermore, a mutated NF-κB binding site in the cyclin D1 promoter fully abrogated the Id2-induced transcription of cyclin D1. Taken together, these data indicate that Id2 induces SCC tumor growth and proliferation through the NF-κB/cyclin D1 pathway.

Anti-apoptotic effects of suppressor of cytokine signaling 3 and 1 in psoriasis

Because of their genetically determined capacity to respond to pro-inflammatory stimuli, keratinocytes have a crucial role in the pathogenesis of psoriasis. Upon IFN-γ and TNF-α exposure, psoriatic keratinocytes express exaggerated levels of inflammatory mediators, and show aberrant hyperproliferation and terminal differentiation. The thickening of psoriasic skin also results from a peculiar resistance of keratinocytes to cytokine-induced apoptosis. In this study, we investigated on the molecular mechanisms concurring to the resistance of psoriatic keratinocytes to cell death, focusing on the role having suppressor of cytokine signaling (SOCS)1 and SOCS3, two molecules abundantly expressed in IFN-γ/TNF-α-activated psoriatic keratinocytes, in sustaining anti-apoptotic pathways. We found that SOCS1 and SOCS3 suppress cytokine-induced apoptosis by sustaining the activation of the PI3K/AKT pathway in keratinocytes. The latter determines the activation of the anti-apoptotic NF-κB cascade and, in parallel, the inhibition of the pro-apoptotic BAD function in keratinocytes. For the first time, we report that phosphorylated AKT and phosphorylated BAD are strongly expressed in lesional psoriatic skin, compared with healthy or not lesional skin, and they strictly correlate to the high expression of SOCS1 and SOCS3 molecules in the psoriatic epidermis. Finally, the depletion of SOCS1 and SOCS3, as well as the chemical inactivation of PI3K activity in psoriatic keratinocytes, definitively unveils the role of PI3K/AKT cascade on the resistance of diseased keratinocytes to apoptosis.

Id-1 and the p65 subunit of NF-κB promote migration of nasopharyngeal carcinoma cells and are correlated with poor prognosis

Inhibitor of differentiation (Id)-1 and nuclear factor-kappa B (NF-κB) have been detected in many malignant tumors, and their presence has been correlated with the metastatic potential of these tumors. This study was undertaken to investigate the prognostic significance of the expression of Id-1 and the p65 subunit of NF-κB (NF-κB/p65) and the proteins' roles in the invasion process of nasopharyngeal carcinoma (NPC) cells. The messenger RNA (mRNA) and protein levels of Id-1 and NF-κB/p65 in normal nasopharyngeal epithelial cells and NPC cell lines were examined using reverse transcription-PCR and western blot analysis, whereas the mRNA and protein levels of Id-1 and NF-κB/p65 in clinical NPC specimens were determined by reverse transcription-PCR and immunohistochemistry. Short hairpin RNA (shRNA) was used to silence Id-1 and NF-κB/p65 to allow for the examination of matrix metalloproteinase (MMP)-9 expression and migratory capacity changes in CNE-2 cells. Multivariate Cox analysis revealed that elevated Id-1 expression was a significant independent predictor of the 5 year overall survival rate (hazards ratio = 16.720, P = 0.005). Furthermore, elevated expression of both Id-1 and NF-κB/p65 was associated with poor clinical survival (P = 0.049). Targeting Id-1 and NF-κB/p65 mRNA with shRNA in CNE-2 cells inhibited MMP-9 expression and decreased the migratory capacity of CNE-2 cells. In conclusion, Id-1 expression is a novel independent prognostic marker molecule that helps identify NPC patients with a poor prognosis. Additionally, combined analysis of Id-1 and NF-κB/p65 can be useful for identifying patients at risk for unfavorable clinical outcomes. Id-1 or/and NF-κB/p65 enhanced tumor cell migration, which is associated with the secretion of MMP-9.

iNOS activation regulates β-catenin association with its partners in endothelial cells

BACKGROUND

Signals that disrupt β-catenin association to cadherins may influence the translocation of β-catenin to the nucleus to regulate transcription. Post-translational modification of proteins is a signalling event that may lead to changes in structural conformation, association or function of the target proteins. NO and its derivatives induce nitration of proteins during inflammation. It has been described that animals treated with NO donors showed increased permeability due to modulation of VE-cadherin/catenin complex. We, therefore, aim to evaluate the effect of iNOS activation on the expression, nuclear localisation and function of β-catenin in endothelial cells.

METHODOLOGY/PRINCIPAL FINDINGS

Expression, nuclear localisation, post-translational modifications and function of β-catenin was analysed by cell fractionation, immunoprecipitation, immunoblots, QRT-PCR and permeability assays in murine endothelial cells (H5V). Influence of macrophage activation on expression of VE-cadherin/p120-catenin/β-catenin complex in co-cultured H5V cells was also assessed. Activation of macrophages to produce NO provoked a decrease in VE-cadherin/p120-catenin/β-catenin expression in H5V cells. Phosphorylation of β-catenin, p120-catenin and VE-cadherin, and reduction in the barrier properties of the cell monolayer was associated with iNOS induction. Moreover, high NO levels provoked nitration of β-catenin, and induced its translocation to the nucleus. In the nucleus of NOS activated cells, nitration levels of β-catenin influenced its association with TCF4 and p65 proteins. High levels of NO altered β-catenin mediated gene expression of NFκB and Wnt target genes without affecting cell viability.

CONCLUSIONS

NOS activity modulates β-catenin post-translational modifications, function and its association with different partners to promote endothelial cell survival. Therapeutic manipulation of iNOS levels may remove a critical cytoprotective mechanism of importance in tumour angiogenesis.

An essential role for the Id1/PI3K/Akt/NFkB/survivin signalling pathway in promoting the proliferation of endothelial progenitor cells in vitro

The enhancement of re-endothelialisation is a critical therapeutic option for repairing injured blood vessels. Endothelial progenitor cells (EPCs) are the major source of cells that participate in endothelium repair and contribute to re-endothelialisation by reducing neointima formation after vascular injury. The over-expression of the inhibitor of differentiation or DNA binding 1 (Id1) significantly improved EPC proliferation. This study aimed to investigate the effects of Id1 on the phosphatidylinositol-3-kinase (PI3K)/Akt/nuclear factor kappa B (NFκB)/survivin signalling pathway and its significance in promoting EPC proliferation in vitro. Spleen-derived EPCs were cultured as previously described. Id1 was presented at low levels in EPCs, and was rapidly up-regulated by stimulation with vascular endothelial growth factor. We demonstrated that transient transfection of Id1 into EPCs activated the PI3K/Akt/NFκB/survivin signalling pathway and promoted EPC proliferation. The proliferation of EPCs was extensively inhibited by silencing of endogenous Id1, and knockdown of Id1 expression led to suppression of PI3K/Akt/NFκB/survivin signalling pathway in EPCs. In addition, blockade by the PI3K-specific inhibitor LY294002, Akt inhibitor, the NFκB inhibitor BAY 11-7082, the survivin inhibitor Curcumin, or the survivin inhibitor YM155 reduced the effects of Id1 transfection. These results suggest that the Id1/PI3K/Akt/NFκB/survivin signalling pathway plays a critical role in EPC proliferation. The Id1/PI3K/Akt/NFκB/survivin signalling pathway may represent a novel therapeutic target in the prevention of restenosis after vascular injury.

Cellular and molecular mechanisms of renal fibrosis

Renal fibrosis, particularly tubulointerstitial fibrosis, is the common final outcome of almost all progressive chronic kidney diseases. Renal fibrosis is also a reliable predictor of prognosis and a major determinant of renal insufficiency. Irrespective of the initial causes, renal fibrogenesis is a dynamic and converging process that consists of four overlapping phases: priming, activation, execution and progression. Nonresolving inflammation after a sustained injury sets up the fibrogenic stage (priming) and triggers the activation and expansion of matrix-producing cells from multiple sources through diverse mechanisms, including activation of interstitial fibroblasts and pericytes, phenotypic conversion of tubular epithelial and endothelial cells and recruitment of circulating fibrocytes. Upon activation, matrix-producing cells assemble a multicomponent, integrin-associated protein complex that integrates input from various fibrogenic signals and orchestrates the production of matrix components and their extracellular assembly. Multiple cellular and molecular events, such as tubular atrophy, microvascular rarefaction and tissue hypoxia, promote scar formation and ensure a vicious progression to end-stage kidney failure. This Review outlines our current understanding of the cellular and molecular mechanisms of renal fibrosis, which could offer novel insights into the development of new therapeutic strategies.

Targeting survivin in cancer: the cell-signalling perspective

Survivin, a prominent anticancer target, is ubiquitously expressed in a plethora of cancers and the evolving complexity in functional regulation of survivin is yet to be deciphered. However, pertaining to the recent studies, therapeutic modulation of survivin is critically regulated by interaction with prominent cell-signalling pathways [HIF-1α, HSP90, PI3K/AKT, mTOR, ERK, tumour suppressor genes (p53, PTEN), oncogenes (Bcl-2, Ras)] and a wide range of growth factors (EGFR, VEGF, among others). In our article we discuss, in detail, an overview of the recent developments in the pharmacological modulation of survivin via cell-signalling paradigms and antisurvivin therapeutics, along with an outlook on therapeutic management of survivin in drug-resistant cancers.

Recently identified biomarkers that promote lymph node metastasis in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is a heterogeneous cancer that arises in the upper aerodigestive tract. Despite advances in knowledge and treatment of this disease, the five-year survival rate after diagnosis of advanced (stage 3 and 4) HNSCC remains approximately 50%. One reason for the large degree of mortality associated with late stage HNSCC is the intrinsic ability of tumor cells to undergo locoregional invasion. Lymph nodes in the cervical region are the primary sites of metastasis for HNSCC, occurring before the formation of distant metastases. The presence of lymph node metastases is strongly associated with poor patient outcome, resulting in increased consideration being given to the development and implementation of anti-invasive strategies. In this review, we focus on select proteins that have been recently identified as promoters of lymph node metastasis in HNSCC. The discussed proteins are involved in a wide range of critical cellular functions, and offer a more comprehensive understanding of the factors involved in HNSCC metastasis while additionally providing increased options for consideration in the design of future therapeutic intervention strategies.