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ERG binding sites on NOTCH1 and NOTCH2 promoters and primer sequences used to amplify these locations.

The oncogenic activation of the ETS-related gene (ERG) due to gene fusions is present in over half of prostate cancers in Western countries. Because of its high incidence and oncogenic role, ERG and components of ERG network have emerged as potential drug targets for prostate cancer. Utilizing gene expression datasets, from matched normal and prostate tumor epithelial cells, an association of NOTCH transcription factors with ERG expression status was identified, confirming that NOTCH factors are direct transcriptional targets of ERG. Inhibition of ERG in TMPRSS2-ERG–positive VCaP cells led to decreased levels of NOTCH1 and 2 proteins and downstream transcriptional targets and partially recapitulated the phenotypes associated with ERG inhibition. Regulation of NOTCH1 and 2 genes by ERG were also noted with ectopic ERG expression in LNCaP (ERG-negative prostate cancer) and RWPE-1 (benign prostate–derived immortalized) cells. Furthermore, inhibition of NOTCH by the small-molecule γ-secretase inhibitor 1, GSI-1, conferred an increased sensitivity to androgen receptor (AR) inhibitors (bicalutamide and enzalutamide) or the androgen biosynthesis inhibitor (abiraterone) in VCaP cells. Combined treatment with bicalutamide and GSI-1 showed strongest inhibition of AR, ERG, NOTCH1, NOTCH2, and PSA protein levels along with decreased cell growth, cell survival, and enhanced apoptosis. Intriguingly, this effect was not observed in ERG-negative prostate cancer cells or immortalized benign/normal prostate epithelial cells. These data underscore the synergy of AR and NOTCH inhibitors in reducing the growth of ERG-positive prostate cancer cells.Implications: Combinational targeting of NOTCH and AR signaling has therapeutic potential in advanced ERG-driven prostate cancers. Mol Cancer Res; 15(10); 1308–17. ©2017 AACR.

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Purpose: To determine whether curcumin would inhibit IκB kinase β (IKKβ) kinase activity and suppress expression of proinflammatory cytokines in head and neck squamous cell carcinoma cancer (HNSCC) patients.Experimental Design: Saliva was collected before and after subjects chewed curcumin tablets. Protein was extracted and IKKβ kinase activity measured. Interleukin (IL)-6 and IL-8 levels in the salivary supernatants were measured by ELISA. IL-6, IL-8, and other interleukin were also measured independently with ELISA to confirm the inhibitory effect of curcumin on expression and secretion of salivary cytokines.Results: Curcumin treatment led to a reduction in IKKβ kinase activity in the salivary cells of HNSCC patients (P < 0.05). Treatment of UM-SCC1 cells with curcumin as well as with post-curcumin salivary supernatant showed a reduction of IKKβ kinase activity. Significant reduction of IL-8 levels (P < 0.05) was seen in post-curcumin samples from patients with dental caries. Although there was reduced IL-8 expression in 8 of 21 post-curcumin samples of HNSCC patients, the data did not reach statistical significance. Saliva samples from HNSCC patients were also analyzed in a blinded fashion for expression of cytokines. IL-10, IFN-γ, IL-12p70, and IL-2 clustered together, and granulocyte macrophage colony stimulating factor and TNF-α clustered together. Log10 ratio analysis showed decrease in expression of all nine cytokines in both the salivary supernatant and salivary cells of curcumin-treated samples.Conclusions: Curcumin inhibited IKKβ kinase activity in the saliva of HNSCC patients, and this inhibition correlated with reduced expression of a number of cytokines. IKKβ kinase could be a useful biomarker for detecting the effect of curcumin in head and neck cancer. Clin Cancer Res; 17(18); 5953–61. ©2011 AACR.

Previous experiments have shown that curcumin or cisplatin treatment suppresses growth of head and neck squamous cell carcinoma (HNSCC). To study the potential cooperative effect of both agents, two HNSCC cell lines were treated with curcumin or cisplatin alone or in combination. In vivo studies consisted of intravenous tail vein injection of liposomal curcumin, with intraperitoneal cisplatin, into nude mice growing xenograft HNSCC tumors. Introduction of curcumin and suboptimal concentrations of cisplatin showed a significant suppressive effect compared with treatment with either agent alone. Reduced expression of cyclin D1, IκBα, phospho-IκBα, and IKKβ occurred in cisplatin- and curcumin-treated cell lines. Confocal microscopy showed expression of IKKβ in the nucleus of the cell lines. Chromatin immunoprecipitation assay on DNA isolated from IKKβ immunoprecipitated samples showed PCR amplification of interleukin-8 promoter sequences, a binding site of NFκB, indicating an interaction between IKKβ and NFκB. Curcumin inhibited IKKβ in the cytoplasm and nucleus, leading to reduced NFκB activity, with no effect on phospho-AKT. In vivo studies showed significant growth inhibition of xenograft tumors treated with a combination of liposomal curcumin and cisplatin. The suppressive effect of curcumin was mediated through inhibition of cytoplasmic and nuclear IKKβ, resulting in inhibition of NFκB activity. Cisplatin treatment led to cellular senescence, indicating an effect mediated by p53 activation. The mechanisms of the two agents through different growth signaling pathways suggest potential for the clinical use of subtherapeutic doses of cisplatin in combination with curcumin, which will allow effective suppression of tumor growth while minimizing the toxic side effects of cisplatin. Mol Cancer Ther; 9(10); 2665–75. ©2010 AACR.

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Supplementary Table 1 from Curcumin Enhances the Effect of Cisplatin in Suppression of Head and Neck Squamous Cell Carcinoma via Inhibition of IKKβ Protein of the NFκB Pathway

Supplementary Information PDF file - 24991K, Hyperactivated c-Jun N-terminal Kinase as a Therapeutic Target in pVHL-Deficient Renal Cell Carcinomas. Supplementary Materials and Methods. Six (6) supplementary figures. Two (2) supplementary tables. Supplementary Figure S1. pVHL and HIF1� levels in isogenic pairs of RCC cell lines. Supplementary Figure S2. JNK regulates AP1 activity. Supplementary Figure S3. CARD9 silencing inhibits TAK1 functional activity. Supplementary Figure S4. JNK/AP1-dependent EMT in pVHL-deficient RCCs. Supplementary Figure S5. Changes in expression of cadherins and transcription factors resulting from pharmacologic inhibition of JNK in pVHL-deficient cells Supplementary Figure S6. Inhibition of JNK or c-Jun reduces the invasiveness of pVHL-deficient cells. Supplementary Table 1: Phospho-c-Jun Staining in RCC Specimens

Liquid biopsies are gaining more traction as non-invasive tools for the diagnosis and monitoring of cancer. In a new paradigm of cancer treatment, a synergistic botanical drug combination (APG-157) consisting of multiple molecules, is emerging as a new class of cancer therapeutics, targeting multiple pathways and providing a durable clinical response, wide therapeutic window and high level of safety. Monitoring the efficacy of such drugs involves assessing multiple molecules and cellular events simultaneously. We report, for the first time, a methodology that uses circulating plasma cell-free RNA (cfRNA) as a sensitive indicator of patient response upon drug treatment. Plasma was collected from six patients with head and neck cancer (HNC) and four healthy controls receiving three doses of 100 or 200 mg APG-157 or placebo through an oral mucosal route, before treatment and on multiple points post-dosing. Circulating cfRNA was extracted from plasma at 0-, 3- and 24-hours post-treatment, followed by RNA sequencing. We performed comparative analyses of the circulating transcriptome and were able to detect significant perturbation following APG-157 treatment. Transcripts associated with inflammatory response, leukocyte activation and cytokine were upregulated upon treatment with APG-157 in cancer patients, but not in healthy or placebo-treated patients. A platelet-related transcriptional signature could be detected in cancer patients but not in healthy individuals, indicating a platelet-centric pathway involved in the development of HNC. These results from a Phase 1 study are a proof of principle of the utility of cfRNAs as non-invasive circulating biomarkers for monitoring the efficacy of APG-157 in HNC.

Receptor tyrosine kinases (RTKs) are cell surface receptors that bind growth factor ligands and initiate cellular signaling. Of the 20 classes of RTKs, 7 classes, I-V, VIII, and X, are linked to head and neck cancers (HNCs). We focus on the first class of RTK, epidermal growth factor receptor (EGFR), as it is the most thoroughly studied class. EGFR overexpression is observed in 20% of tumors, and expression of EGFR variant III is seen in 15% of aggressive chemoradiotherapy resistant HNCs. Currently, the EGFR monoclonal antibody (mAb) cetuximab is the only FDA approved RTK-targeting drug for the treatment of HNCs. Clinical trials have also included EGFR mAbs, with tyrosine kinase inhibitors, and small molecule inhibitors targeting the EGFR, MAPK, and mTOR pathways. Additionally, Immunotherapy has been found to be effective in 15 to 20% of patients with recurrent or metastatic HNC as a monotherapy. Thus, attempts are underway for the combinatorial treatment of immunotherapy and EGFR mAbs to determine if the recruitment of immune cells in the tumor microenvironment can overcome EGFR resistance.

We have observed overexpression of PACS-1, a cytosolic sorting protein in primary cervical tumors. Absence of exonic mutations and overexpression at the RNA level suggested a transcriptional and/or posttranscriptional regulation. University of California Santa Cruz genome browser analysis of PACS-1 micro RNAs (miR), revealed two 8-base target sequences at the 3′ terminus for hsa-miR-34a and hsa-miR-449a. Quantitative RT-PCR and Northern blotting studies showed reduced or loss of expression of the two microRNAs in cervical cancer cell lines and primary tumors, indicating dysregulation of these two microRNAs in cervical cancer. Loss of PACS-1 with siRNA or exogenous expression of hsa-miR-34a or hsa-miR-449a in HeLa and SiHa cervical cancer cell lines resulted in DNA damage response, S-phase cell cycle arrest, and reduction in cell growth. Furthermore, the siRNA studies showed that loss of PACS-1 expression was accompanied by increased nuclear γH2AX expression, Lys(382)-p53 acetylation, and genomic instability. PACS-1 re-expression through LNA-hsa-anti-miR-34a or -449a or through PACS-1 cDNA transfection led to the reversal of DNA damage response and restoration of cell growth. Release of cells post 24-h serum starvation showed PACS-1 nuclear localization at G(1)-S phase of the cell cycle. Our results therefore indicate that the loss of hsa-miR-34a and hsa-miR-449a expression in cervical cancer leads to overexpression of PACS-1 and suppression of DNA damage response, resulting in the development of chemo-resistant tumors.

The oncogenic activation of the ETS-related gene (ERG) due to gene fusions is present in over half of prostate cancers in Western countries. Because of its high incidence and oncogenic role, ERG and components of ERG network have emerged as potential drug targets for prostate cancer. Utilizing gene expression datasets, from matched normal and prostate tumor epithelial cells, an association of NOTCH transcription factors with ERG expression status was identified, confirming that NOTCH factors are direct transcriptional targets of ERG. Inhibition of ERG in TMPRSS2-ERG–positive VCaP cells led to decreased levels of NOTCH1 and 2 proteins and downstream transcriptional targets and partially recapitulated the phenotypes associated with ERG inhibition. Regulation of NOTCH1 and 2 genes by ERG were also noted with ectopic ERG expression in LNCaP (ERG-negative prostate cancer) and RWPE-1 (benign prostate–derived immortalized) cells. Furthermore, inhibition of NOTCH by the small-molecule γ-secretase inhibitor 1, GSI-1, conferred an increased sensitivity to androgen receptor (AR) inhibitors (bicalutamide and enzalutamide) or the androgen biosynthesis inhibitor (abiraterone) in VCaP cells. Combined treatment with bicalutamide and GSI-1 showed strongest inhibition of AR, ERG, NOTCH1, NOTCH2, and PSA protein levels along with decreased cell growth, cell survival, and enhanced apoptosis. Intriguingly, this effect was not observed in ERG-negative prostate cancer cells or immortalized benign/normal prostate epithelial cells. These data underscore the synergy of AR and NOTCH inhibitors in reducing the growth of ERG-positive prostate cancer cells. Implications: Combinational targeting of NOTCH and AR signaling has therapeutic potential in advanced ERG-driven prostate cancers. Mol Cancer Res; 15(10); 1308–17. ©2017 AACR.

A procedure is described to measure curcumin (C), demethoxycurcumin (DMC), bisdemethoxycurcumin (BDMC), tetrahydrocurcumim (TC) and their glucuronidated metabolites (CG, DMCG, and BDMCG) in plasma, brain, liver and tumor samples. The procedure involves converting the analytes to their boron difluoride derivatives and analyzing them by combined liquid chromatography coupled to an ion trap mass spectrometer operating in the negative ion MSn scan mode. The method has superb limits of detection of 0.01 nM for all curcuminoids and 0.5 nM for TC and the glucuroniated metabolites, and several representative chromatograms of biological samples containing these analytes are provided. In addition, the pharmacokinetic profile of these compounds in one human who daily consumed an over-the-counter curcuminoid product shows the peak and changes in circulating concentrations achieved by this mode of administration.

Background Although curcumin's effect on head and neck cancer has been studied in vitro and in vivo, to the authors' knowledge its efficacy is limited by poor systemic absorption from oral administration. APG-157 is a botanical drug containing multiple polyphenols, including curcumin, developed under the US Food and Drug Administration's Botanical Drug Development, that delivers the active components to oromucosal tissues near the tumor target. Methods A double-blind, randomized, placebo-controlled, phase 1 clinical trial was conducted with APG-157 in 13 normal subjects and 12 patients with oral cancer. Two doses, 100 mg or 200 mg, were delivered transorally every hour for 3 hours. Blood and saliva were collected before and 1 hour, 2 hours, 3 hours, and 24 hours after treatment. Electrocardiograms and blood tests did not demonstrate any toxicity. Results Treatment with APG-157 resulted in circulating concentrations of curcumin and analogs peaking at 3 hours with reduced IL-1β, IL-6, and IL-8 concentrations in the salivary supernatant fluid of patients with cancer. Salivary microbial flora analysis showed a reduction in Bacteroidetes species in cancer subjects. RNA and immunofluorescence analyses of tumor tissues of a subject demonstrated increased expression of genes associated with differentiation and T-cell recruitment to the tumor microenvironment. Conclusions The results of the current study suggested that APG-157 could serve as a therapeutic drug in combination with immunotherapy. Lay summary Curcumin has been shown to suppress tumor cells because of its antioxidant and anti-inflammatory properties. However, its effectiveness has been limited by poor absorption when delivered orally. Subjects with oral cancer were given oral APG-157, a botanical drug containing multiple polyphenols, including curcumin. Curcumin was found in the blood and in tumor tissues. Inflammatory markers and Bacteroides species were found to be decreased in the saliva, and immune T cells were increased in the tumor tissue. APG-157 is absorbed well, reduces inflammation, and attracts T cells to the tumor, suggesting its potential use in combination with immunotherapy drugs.

The last decade has brought about an unexpected rise in oropharyngeal squamous cell carcinoma (OPSCC) primarily in white males from the ages of 40-55years, with limited exposure to alcohol and tobacco. This subset of squamous cell carcinoma (SCC) has been found to be associated with human papillomavirus infection (HPV). Other Head and Neck Squamous Cell carcinoma (HNSCC) subtypes include oral cavity, hypopharyngeal, nasopharyngeal, and laryngeal SCC which tend to be HPV negative. HPV associated oropharyngeal cancer has proven to differ from alcohol and tobacco associated oropharyngeal carcinoma in regards to the molecular pathophysiology, presentation, epidemiology, prognosis, and improved response to chemoradiation therapy. Given the improved survival of patients with HPV associated SCC, efforts to de-intensify treatment to decrease treatment related morbidity are at the forefront of clinical research. This review will focus on the important differences between HPV and tobacco related oropharyngeal cancer. We will review the molecular pathogenesis of HPV related oropharyngeal cancer with an emphasis on new paradigms for screening and treating this disease.

Gigaxonin, the product of GAN gene localized to chromosome 16, is associated with the early onset neuronal degeneration disease giant axonal neuropathy (GAN). Gigaxonin is an E3 ubiquitin ligase adaptor protein involved in intermediate filament processing in neural cells, and vimentin filaments in fibroblasts. Mutations of the gene cause pre-neural filaments to accumulate and form giant axons resulting in the inhibition of neural cell signaling. Analysis of the catalog of somatic mutations in cancer, driver DB and IDGC data portal databases containing 21,000 tumor genomic sequences has identified GAN patient mutations in cancer cell lines and primary tumors. The database search has also shown the presence of identical missense and nonsense gigaxonin mutations in GAN and colon cancer. These mutations frequently occur in the domains associated with protein homodimerization and substrate interaction such as Broad-Complex, Tramtrack and Bric a brac (BTB), BTB associated C-terminal KELCH (BACK), and KELCH repeats. Analysis of the International HapMap Project database containing 1200 normal genomic sequences has identified a single nucleotide polymorphism (SNP), rs2608555, in exon 8 of the gigaxonin sequence. While this SNP is present in >40 % of Caucasian population, it is present in less than 10 % of Japanese and Chinese populations. Although the role of gigaxonin polymorphism is not yet known, CFTR and MDR1 gene studies have shown that silent mutations play a role in the instability and aberrant splicing and folding of mRNAs. We believe that molecular and functional investigation of gigaxonin mutations including the exon 8 polymorphism could lead to an improved understanding of the relationship between GAN and cancer.

Gigaxonin, the protein product of the Giant axonal neuropathy (GAN) gene, is a E3 ubiquitin ligase involved in neural cell and fibroblast intermediate filament processing. We have previously shown that Gigaxonin interacts with p16 in cisplatin-mediated ubiquitination of NF-κB. We analyzed cervical and head and neck cancer cell lines and primary tumors and have found exon 8 c.1293C>T single nucleotide polymorphism (SNP) to occur in both HPV positive and negative tumor cells lines and primary tumors. The prevalence of this SNP in the tumor samples was double that of the normal population (47.25% vs. 22%) and there was no relationship to HPV status. Cell lines containing the SNP showed higher expression of gigaxonin, and an inverse relationship to in vitro tumor cell line growth and cisplatin sensitivity. There was a direct relationship between the expression of gigaxonin and e-cadherin and inverse relationship to the expression of twist, snail and n-cadherin. CRISPR-Cas9 mediated conversion of T to C allele in gigaxonin overexpressing cervical cancer cell line ME 180 resulted in decreased gigaxonin expression accompanied by increased expression of twist, and snail and increased in vitro cell growth. Re-expression of gigaxonin in the CRISPR-Cas9 clone with a plasmid gigaxonin cDNA construct resulted in decreased expression of twist pointing to gigaxonin mediated downregulation of the EMT marker. We therefore hypothesize that GAN, associated with the neurodegenerative disease, is also a human tumor cell growth suppressor gene. Citation Format: Mysore S. Veena, Daniel Sanghoon Shin, Chan Jeong, Jenna R. Chatoff, Natarajan Venkatesan, Saroj K. Basak, David Gray, Sharon P. Wilczynski, Sharon P. Wilczynski, Steven J. Gray, Donald B. Kohn, Marilene B. Wang, Eri S. Srivatsan. Inverse relationship between Giant Axonal Neuropathy gene expression and EMT in human tumors [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5986.

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer, with 600,000 new cases every year worldwide. Although chemotherapeutics exist, five-year survival is only 50%. New strategies to overcome drug resistance are required to improve HNSCC treatment. Curcumin-difluorinated (CDF), a synthetic analog of curcumin, was packaged in liposomes and used to evaluate growth inhibition of cisplatin resistant HNSCC cell lines CCL-23R and UM-SCC-1R generated from the parental cell lines CCL-23 and UM-SCC-1 respectively. Growth inhibition in vitro and expression levels of the CD44 (cancer stem cell marker), cytokines, and growth factors were investigated after liposomal CDF treatment. The in vivo growth inhibitory effect of liposomal CDF was evaluated in the nude mice xenograft tumor model of UM-SCC-1R and the inhibition of CD44 was measured. Treatment of the resistant cell lines in vitro with liposomal CDF resulted in a statistically significant growth inhibition (p < 0.05). The nude mice xenograft study showed a statistically significant tumor growth inhibition of UM-SCC-1R cells and a reduction in the expression of CD44 (p < 0.05), indicating an inhibitory effect of liposomal CDF on CSCs. Our results demonstrate that delivery of CDF through liposomes may be an effective method for the treatment of cisplatin resistant HNSCC.

The molecular mechanism of p16-mediated senescence in cisplatin-treated cancer cells is not fully understood. Here we show that cisplatin treatment of head and neck cancer cells results in nuclear transport of p16 leading to a molecular modification of NFκB. Chromatin immunoprecipitation assays show that this modification is associated with the inhibition of NFκB interacting with its DNA binding sequences, leading to decreased expression of NFκB-transcribed proteins. LCMS proteomic analysis of LAP-TAP-purified proteins from HeLa cells containing a tetracycline-inducible GFP-S peptide-NFκB expression system identified gigaxonin, an ubiquitin E3 ligase adaptor, as an NFκB-interacting protein. Immunoblotting and siRNA studies confirmed the NFκB-gigaxonin interaction and the dependence of this binding on p16-NFκB binding. Using gel shift assays, we have confirmed p16-NFκB and gigaxonin-NFκB interactions. Furthermore, we have observed increased NFκB ubiquitination with cisplatin treatment that is abolished in the absence of p16 and gigaxonin expression. Analysis of 103 primary tumors has shown that increased nuclear p16 expression correlates with enhanced survival of head and neck cancer patients (p < 0.0000542), indicating the importance of nuclear p16 expression in prognosis. Finally, p16 expression is associated with reduced cytokine expression and the presence of human papilloma virus in chemoradiation-sensitive basaloid tumors. However, the absence of p16 expression is associated with enhanced cytokine expression and the absence of human papilloma virus in aggressive tumors. These results clearly demonstrate that nuclear p16 and gigaxonin play an important role in chemosensitivity of head and neck cancers through ubiquitination of NFκB.

Cloning and sequencing of 5.5kb deletion at chromosome 11q13.1 from the HeLa cells, tumorigenic hybrids and two fibroblast cell lines has revealed homologous recombination between AluSx and AluY resulting in the deletion of intervening sequences. Long-range PCR of the 5.5kb sequence in 494 normal lymphocyte samples showed heterozygous deletion in 28.3% of African- American ancestry samples but only in 4.8% of Caucasian samples (p

e17572 Background: Natural botanical drugs, such as curcumin, resveratrol and related flavonoids, are under clinical studies. Previous pilot study of curcumin, a polyphenol, for normal and patients with oral squamous cell carcinoma (OSCC) showed significant inhibition of inflammatory cytokines in saliva. Phase I investigation was performed on APG-157 to evaluate the potential utility an as oral drug for the treatment of OSCC. Methods: A double-blind, randomized, placebo-controlled phase I clinical trial was conducted with a botanical preparation containing a combination of curcumin related polyphenol molecules (pharmaceutical name APG-157). 12 Subjects with oral cancer and 13 normal control subjects were recruited. Two doses of the drug, 3x100 mg and 3x200 mg, were tested. The drug was administered orally each hour for 3 consecutive hours. Blood and saliva were collected pre-treatment and 1, 2, 3, and 24 hours post-treatment. Salivary cells and supernatants were analyzed for the expression of cytokines by multiplex ELISA and microbial content by 16S RNA sequence. Pre- and post-treatment tumor biopsies of one subject were studied for expression using the RNA seq and immunofluorescence (IF). Results: This study did not reveal any toxicity and there was a dose dependent inhibition of inflammatory cytokines, IL-1β, TNF-alpha and IL-8 in the salivary supernatant of cancer subjects treated with the drug. Tumor RNA-seq revealed down regulation of gene ontologies of cell adhesion, cell cycle and cell division and up regulation of generation of precursor metabolite/energy in the post-treatment tumor sample. Microbiome study showed significant decrease in Bacterioides after 24 hours of treatment. There was also a trend of decreasing Bacteroides among other cancer subjects treated with APG-157. IF showed a marked increase in the number of CD4, CD8 T cells in post-treatment tumor. PD-L1 expression was up-regulated in the post-treatment tumor sample. Conclusions: APG-157 is found to be safe and toxicity was not observed. The drug has shown a decrease in inflammatory cytokines. Moreover, there was a markedly increased CD4, CD8 T cells infiltration on a subject and decreased Bacteriodes microbial population after APG-157 treatment suggesting that it might have potential synergistic effect with immune checkpoint blockade immunotherapy. Decreased expression of cell growth related genes and increased expression of growth inhibitory genes pointed to a potential anti-tumor activity of APG-157.

Clear cell renal cell carcinomas (RCC), the major histologic subtype of RCC accounting for more than 80% of cases, are typified by biallelic inactivation of the von Hippel–Lindau (VHL) tumor suppressor gene. Although accumulation of hypoxia-inducible factor alpha (HIF-α) is the most well-studied effect of VHL inactivation, direct inhibition of HIFα or restoration of wild-type pVHL protein expression has not proved readily feasible, given the limitations associated with pharmacologic targeting of transcription factors (i.e., HIF-α) and gene replacement therapy of tumor suppressor genes (i.e., VHL). Here, we have established that phosphorylated c-Jun, a substrate of the c-Jun-NH2-kinase (JNK), is selectively activated in clear cell RCC patient specimens. Using multiple isogenic cell lines, we show that HIF-α–independent JNK hyperactivation is unique to the pVHL-deficient state. Importantly, pVHL-deficient RCCs are dependent upon JNK activity for in vitro and in vivo growth. A multistep signaling pathway that links pVHL loss to JNK activation involves the formation of a CARD9/BCL10/TRAF6 complex as a proximal signal to sequentially stimulate TAK1 (MAPKKK), MKK4 (MAPKK), and JNK (MAPK). JNK stimulates c-Jun phosphorylation, activation, and dimerization with c-Fos to form a transcriptionally competent AP1 complex that drives transcription of the Twist gene and induces epithelial–mesenchymal transition. Thus, JNK represents a novel molecular target that is selectively activated in and drives the growth of pVHL-deficient clear cell RCCs. These findings can serve as the preclinical foundation for directed efforts to characterize potent pharmacologic inhibitors of the JNK pathway for clinical translation. Cancer Res; 73(4); 1374–85. ©2012 AACR.

We and others have shown that the cystatin E/M gene is inactivated in primary human tumors, pointing to its role as a tumor suppressor gene. However, the molecular mechanism of tumor suppression is not yet understood. Using plasmid-directed cystatin E/M gene overexpression, a lentivirus-mediated tetracycline-inducible vector system, and human papillomavirus 16 (HPV 16) E6 and E7 gene-immortalized normal human epidermal keratinocytes, we demonstrated intracellular and non-cell-autonomous apoptotic growth inhibition of tumor cell lines and that growth inhibition is associated with cytoplasmic retention of NF-κB. We further demonstrated decreased phosphorylation of IκB kinase (IKKβ) and IκBα in the presence of tumor necrosis factor alpha (TNF-α), confirming the role of cystatin E/M in the regulation of the NF-κB signaling pathway. Growth suppression of nude mouse xenograft tumors carrying a tetracycline-inducible vector system was observed with the addition of doxycycline in drinking water, confirming that the cystatin E/M gene is a tumor suppressor gene. Finally, immunohistochemical analyses of cervical carcinoma in situ and primary tumors have shown a statistically significant inverse relationship between the expression of cystatin E/M and cathepsin L and a direct relationship between the loss of cystatin E/M expression and nuclear expression of NF-κB. We therefore propose that the cystatin E/M suppressor gene plays an important role in the regulation of NF-κB.

Cellular senescence is an irreversible arrest of cell growth. Biochemical and morphological changes occur during cellular senescence, including the formation of a unique cellular morphology such as flattened cytoplasm. Function of mitochondria, endoplasmic reticulum and lysosomes are affected resulting in the inhibition of lysosomal and proteosomal pathways. Cellular senescence can be triggered by a number of factors including, aging, DNA damage, oncogene activation and oxidative stress. While the molecular mechanism of senescence involves p16 and p53 tumor suppressor genes and telomere shortening, this review is focused on the mechanism of p16 control. The p16-mediated senescence acts through the retinoblastoma (Rb) pathway inhibiting the action of the cyclin dependant kinases leading to G1 cell cycle arrest. Rb is maintained in a hypophosphorylated state resulting in the inhibition of transcription factor E2F1. Regulation of p16 expression is complex and involves epigenetic control and multiple transcription factors. PRC1 (Pombe repressor complex (1) and PRC2 (Pombe repressor complex (2) proteins and histone deacetylases play an important role in the promoter hypermethylation for suppressing p16 expression. While transcription factors YY1 and Id1 suppress p16 expression, transcription factors CTCF, Sp1 and Ets family members activate p16 transcription. Senescence occurs with the inactivation of suppressor elements leading to the enhanced expression of p16.

Purpose: To determine whether curcumin would inhibit IκB kinase β (IKKβ) kinase activity and suppress expression of proinflammatory cytokines in head and neck squamous cell carcinoma cancer (HNSCC) patients. Experimental Design: Saliva was collected before and after subjects chewed curcumin tablets. Protein was extracted and IKKβ kinase activity measured. Interleukin (IL)-6 and IL-8 levels in the salivary supernatants were measured by ELISA. IL-6, IL-8, and other interleukin were also measured independently with ELISA to confirm the inhibitory effect of curcumin on expression and secretion of salivary cytokines. Results: Curcumin treatment led to a reduction in IKKβ kinase activity in the salivary cells of HNSCC patients (P < 0.05). Treatment of UM-SCC1 cells with curcumin as well as with post-curcumin salivary supernatant showed a reduction of IKKβ kinase activity. Significant reduction of IL-8 levels (P < 0.05) was seen in post-curcumin samples from patients with dental caries. Although there was reduced IL-8 expression in 8 of 21 post-curcumin samples of HNSCC patients, the data did not reach statistical significance. Saliva samples from HNSCC patients were also analyzed in a blinded fashion for expression of cytokines. IL-10, IFN-γ, IL-12p70, and IL-2 clustered together, and granulocyte macrophage colony stimulating factor and TNF-α clustered together. Log10 ratio analysis showed decrease in expression of all nine cytokines in both the salivary supernatant and salivary cells of curcumin-treated samples. Conclusions: Curcumin inhibited IKKβ kinase activity in the saliva of HNSCC patients, and this inhibition correlated with reduced expression of a number of cytokines. IKKβ kinase could be a useful biomarker for detecting the effect of curcumin in head and neck cancer. Clin Cancer Res; 17(18); 5953–61. ©2011 AACR.

Gigaxonin is the protein product of Giant Axonal Neuropathy (GAN) gene and is involved in the processing of intermediate filaments of neural cells and vimentin fibers in fibroblasts. We have shown earlier that gigaxonin is associated with p16 in NFkB ubiquitination of cisplatin sensitive tumor cells. Our studies have shown that there is a direct relationship between the presence of exon 8 SNP (C>T) and expression of giagxonin in cancer cell lines. We have also seen an inverse relationship between exon 8 SNP and tumor recurrence and metastasis. RNA-seq studies of cancer cell lines and primary tumors have shown a direct relationship in the expression of gigaxonin to the expression of e-cadherin and inverse relationship to the expression of Vimentin and Zeb1. Immunohistochemical (IHC) studies of primary head and neck cancers have confirmed the inverse relationship between e-cadherin and vimentin. We hypothesize therefore that gigaxonin is involved in the ubiquitination of vimentin and cancer stem cell markers such as zeb1 resulting in the chemo sensitization of human tumor cells. Citation Format: Albert Ko, Natarajan Venkatesan, Jenna Chatoff, Marco Morselli, Gregory Fishbein, Pascale Bomont, Matteo Pellegrini, Marilene Wang, Eri Srivatsan. GAN gene exon 8 SNP is related to gigaxonin expression and increased expression of e-cadherin in head and neck cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5505.

Purpose: The purpose of this study was to determine whether curcumin would trigger cell death in the head and neck squamous cell carcinoma (HNSCC) cell lines CCL 23, CAL 27, and UM-SCC1 in a dose-dependent fashion. Experimental Design: HNSCC cells were treated with curcumin and assayed for in vitro growth suppression using 3-(4,5-dimethylthiozol-2-yl)-2,5-diphenyl tetrazolium bromide and fluorescence-activated cell sorting analyses. Expression of p16, cyclin D1, phospho-Iκβ, and nuclear factor-κβ (NF-κβ) were measured by Western blotting, gel shift, and immunofluorescence. Results: Addition of curcumin resulted in a dose-dependent growth inhibition of all three cell lines. Curcumin treatment resulted in reduced nuclear expression of NF-κβ. This effect on NF-κβ was further reflected in the decreased expression of phospho-Iκβ-α. Whereas the expression of cyclin D1, an NF-κβ–activated protein, was also reduced, there was no difference in the expression of p16 at the initial times after curcumin treatment. In vivo growth studies were done using nude mice xenograft tumors. Curcumin was applied as a noninvasive topical paste to the tumors and inhibition of tumor growth was observed in xenografts from the CAL27 cell line. Conclusions: Curcumin treatment resulted in suppression of HNSCC growth both in vitro and in vivo. Our data support further investigation into the potential use for curcumin as an adjuvant or chemopreventive agent in head and neck cancer.

We have previously shown TP16 MTS1/CDK41 gene deletion in more than 50% of a cohort of squamous cell carcinoma of the head and neck (SCCHN) patients using polymerase chain reaction (PCR). We have performed fluorescence in situ hybridization (FISH) on paraffin-embedded SCCHN specimens from the same cohort to identify the deletion of TP16 MTS1/CDK41CDK41 gene. Twenty normal and 19 SCCHN specimens were studied. An α-satellite DNA probe specific for chromosome 9 and a cosmid probe for the TP16 MTS1/CDK41CDK41 gene were used. Of the 19 tumors examined by FISH, 6 had homozygous deletions, 7 were hemizygously deleted, and the remaining 6 showed no evidence of deletion of the TP16 MTS1/CDK41 gene. None of the normal specimens showed TP16 gene deletion. Data obtained from FISH highly correlated with the PCR results for the identification of TP16 MTS1/CDK41 gene deletions. Patients with deletion of the TP16 MTS1/CDK41 gene show a greater tendency toward the development of recurrence and metastasis.

Previous molecular genetic studies on HeLa cell (a cervical cancer cell line) derived non-tumorigenic and tumorigenic hybrids have localized a tumor suppressor gene to the long arm of chromosome 11. Analysis of cervical cancer cell lines using chromosome 11 specific probes showed deletion and translocation of 11q13 sequences in five out of eight cell lines. Fluorescence in situ hybridization (FISH), using 11q13 specific probes, has shown interstitial deletion of 11q13 sequences in the HeLa cells. In order to determine whether 11q13 deletions occur in primary cervical tumors, we analysed 36 tumors using 20 different microsatellite and RFLP markers. Semi automated fluorescein based allelotyping was performed to identify loss of heterozygosity (LOH) in tumors. The results showed allelic loss in 17 (47%) tumors. Three different regions of loss, one near MEN1, the second near D11S913, and the third near INT2 locus were observed. The smallest region of deletion overlap at the D11S913 locus was localized to a 300 Kb distance between D11S4908 and D11S5023. Fluorescence in situ hybridization (FISH), using 11q13 specific cosmid and BAC (bacterial artificial chromosome) probes, confirmed allelic deletion in the tumors. PCR analysis further identified homozygous deletion of 11q13 sequences in a primary tumor, in HeLa cells and in two HeLa cell derived tumorigenic hybrid cell lines. The homozygous deletion in the cell lines was mapped to a 5.7 kb sequence of 11q13. We hypothesize therefore that a putative cervical cancer tumor suppressor gene exists within the 300 kb of chromosome 11q13.

Nasopharyngeal carcinoma (NPC) is a malignancy that is particularly prevalent among populations from Southern China and Southeast Asian countries. Evidence for a genetic contribution to the disease has been documented, although the genetic basis for NPC development is not yet fully understood. Previous functional evidence of tumor-suppressive activity on chromosome band 11q13 in NPC was obtained using a microcell-mediated chromosome-transfer approach with HONE1 NPC cells. In the present study, this region was subjected to a detailed investigation of microcell hybrids and their tumor segregants using microsatellite analysis to narrow down the region of tumor-suppressive activity. Fluorescence in situ hybridization was also performed with BAC and cosmid probes to confirm the microsatellite data. The critical region responsible for tumor suppression was narrowed down to a 1.8-Mb interval, which does not tolerate an additional normal allele by chromosome transfer. One or two alleles from either endogenous or exogenous chromosomes at 11q13 were consistently eliminated during tumor growth. Results of this study suggest that a candidate tumor-suppressor gene, not the MEN1 gene, maps between D11S4907 and GSTP1 in NPC.

Objectives/Hypothesis Cyclin D1, a cell cycle regulator localized to chromosome 11q13, is amplified in several human tumors including head and neck squamous cell carcinoma (HNSCC). Amplification and/or overexpression of cyclin D1 have been correlated to a poor prognosis. Deletion of the p16 gene, localized to 9p21, has also been observed in a significant proportion of HNSCC. The p16 gene regulates cyclin D1-CDK4 activity and prevents retinoblastoma tumor suppressor gene phosphorylation, thereby downregulating cellular proliferation. Detection of cyclin D1 amplification and p16 deletion using a simple and sensitive method will be valuable for the development of effective treatment modalities for head and neck cancer. Study Design We have used fluorescence in situ hybridization (FISH) to study cyclin D1 amplification and p16 gene deletion in head and neck tumors. Both single- and dual-color FISH were performed. Methods Paraffin-embedded tissues from 103 patients with HNSCC were analyzed using genomic DNA probes for cyclin D1 and p16. Dual-color FISH was performed with chromosome 11 or 9 centromeric probes as a control. Twenty-eight of these samples were analyzed for p16 expression by immunohistochemistry. Results Cyclin D1 amplification was observed in 30% (31/103) of patients, and p16 deletion in 52% (54/103). Lack of p16 expression was observed in 64% (18/28) of patients. There was a good correlation between the deletion of p16 sequences and the loss of p16 expression (P = .008). Amplification of cyclin D1 had a statistically significant association with recurrence, distant metastasis, and survival at 36 months. There was a significant association between p16 deletion and the development of distant metastases. Cyclin D1 amplification and p16 deletion together correlated with recurrence, distant metastasis, and survival. Conclusions We demonstrate that FISH is a simple and sensitive method for detecting cyclin D1 amplification and p16 deletion in head and neck cancer. Our results suggest that these two genetic aberrations together portend a poorer outcome than either of the abnormalities alone in head and neck cancer.

Gigaxonin, a product of the Giant Axonal Neuropathy (GAN) gene located on chromosome 16, is involved in intermediate filament processing of neural cells and vimentin fibers in fibroblasts. Previous studies have shown an interaction between p16 and gigaxonin in cisplatin mediated ubiquitination of NFkB. Genomic studies have indicated higher frequency (44.25%) of exon 8 single nucleotide polymorphism (SNP) (c.1293 C>T) of gigaxonin in the individuals of Caucasian population compared to normal population (22%). The polymorphism frequency is much lower in individuals of other ethnicities. To determine the relationship to tumors, we analyzed exon 8 polymorphism in HPV positive and negative cervical and head and tumors. Our studies showed a 47.25% polymorphic frequency in these tumors. There was no relationship between the presence of polypmorphism and HPV status. However, there was an inverse relationship between polymorphism and tumor recurrence. Our studies have further shown higher expression of gigaxonin protein in cancer cell lines containing the polymorphic T allele. Growth assays in vitro and in soft agar have shown a direct relationship between the presence of the T allele and slower cell line growth. Our results therefore indicate that in addition to p16 expression, exon 8 SNP could also serve as a diagnostic marker of chemo sensitivity in human tumors. Citation Format: Eri S. Srivatsan, Kimberly J. Hwang, Albert Ko, Jenna R. Chatoff, Saroj K. Basak, Natarajan Venkatesan, Fernando Palma-Diaz, Michael S. Lewis, Pascale Bomont, Marilene B. Wang. Inverse relationship between exon 8 single nucleotide polymorphism (c.1293 C>T) of gigaxonin and human tumor cell growth [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4457. doi:10.1158/1538-7445.AM2017-4457

Background. The neural cell adhesion molecule (NCAM) has numerous isoforms resulting from alternative splicing of mRNA. The 3 major isoforms found in adult tissue are (1) a 120-kDa protein that is linked to the plasma membrane by glycosylphosphatidylinositol; (2) a 140-kDa form that has a transmembrane component and a cytoplasmic tail with unknown function; and (3) a 180-kDa isoform that has an intracellular protein that binds the cytoskeleton. NCAM is capable of homotypic binding and therefore plays a role in cell-cell adhesion for cells expressing the 180-kDa isoform by anchoring groups of cells into epithelial sheets. NCAM-180 is the isoform found in colonocytes, and loss of expression is associated with clinically aggressive colon cancers. Methods. Western blotting and reverse transcriptase-polymerase chain reaction were used to screen commercially available cell lines for NCAM-180 expression. For cell-line pairs with differential NCAM-180 expression, exon analysis was performed with reverse transcriptase-polymerase chain reaction to determine where the molecule was spliced, culminating in failed expression. These results were confirmed with exon analysis in colon cancers harvested at the time of laparotomy. Results. Analysis of a SW480 cell line (derived from a patient's primary colon cancer lesion) revealed NCAM-180 expression, whereas no expression was found in the SW620 cell line (derived from a metastatic lesion from the same patient). Exon analysis of NCAM mRNA transcripts from SW620 revealed that the transcripts were truncated after exon 12. This region correlates to an area between 2 fibronectin-III domains on the NCAM protein. Conclusions. The most common site for NCAM alternative splicing is between the 2 fibronectin-III domains corresponding to the border between exons 12 and 13 of the NCAM gene. Loss of NCAM-180 expression in aggressive colon carcinoma results from a splice defect in the same area, which may result in defective intracellular adhesion between colonocytes. (Surgery 2001;130:834-43.)

Problem: Cyclin D1 is a regulatory factor essential in the progression of the cell cycle from G1 through S phase. Amplification and overexpression of cyclin D1 have been observed in many human cancers including head and neck squamous cell carcinoma (HNSCC). We have previously transfected a HNSCC control cell line (CCL23) with an antisense cyclin D1 plasmid and demonstrated inhibition of cell proliferation in vitro. In this study, we examine whether antisense cyclin D1 could inhibit tumor growth in vivo. Methods/measures: The CCL23 and its antisense cyclin D1 transfected clone (CCL23 AS) were injected into the flanks of nude mice. Tumor growth was monitored weekly. After 5 weeks, tumors were removed and studied for tumor size, cyclin D1 expression, cyclin D1-dependent kinase activity, and retinoblastoma (Rb) phosphorylation. Results: Compared with the control tumors, 11 of 19 antisense tumors were smaller, 7 tumors were of equal size, and 1 tumor was larger. Immunohistochemical analysis with an anti-cyclin D1 antibody demonstrated decreased cyclin D1 expression in CCL23 AS and the smaller antisense tumors. Cyclin D1-dependent kinase activity was reduced in CCL23 AS and the smaller antisense tumors, and this was accompanied by a relative decrease in phosphorylated Rb in these samples. Conclusion: Antisense cyclin D1 inhibits growth of HNSCC tumors. Cyclin D1 expression, cyclin D1-dependent kinase activity, and Rb phosphorylation are decreased in these tumors. Clinical significance: These findings lend support for the potential use of antisense cyclin D1 as gene therapy for HNSCC. (Otolaryngol Head Neck Surg 2001;124:656-62.)

Previous cytogenetic and molecular genetic studies have shown that the HeLa (cervical carcinoma) cell line D98/AH-2 contains two apparently normal copies of chromosome 11 and additional 11q13-25 material translocated onto a chromosome 3 marker. To determine the 11q13 breakpoint, we performed fluorescence in situ hybridization (FISH) using 18 different 11q13 specific BAC (bacterial artificial chromosome) and cosmid probes spanning a 5.6 Mb interval. Markers localized to the multiple endocrine neoplasia type 1 (MEN1) gene (menin) were also included in the analysis. The FISH study identified an interstitial deletion between markers D11S449 and GSTP1, an interval of 2.3 Mb, in the marker chromosome. This deletion did not include the MEN1 gene. Because point mutations and methylations can inactivate the MEN1 gene, single stranded conformational polymorphism (SSCP) and Northern and Western blot analyses were performed with MEN1 specific probes and antibody. SSCP did not reveal mutations of the MEN1 gene in HeLa or in seven other cervical cancer cell lines. Northern and Western blot studies revealed normal levels of expression of this gene in the cervical cancer cell lines as well as in HeLa cell derived tumorigenic hybrids. Because deletions of tumor suppressor genes often occur in cancer progression, we hypothesize that the inactivation of a tumor suppressor gene other than MEN1, localized to the 2.3 Mb interval on 11q13, might play a role in the abnormal growth behavior of HeLa cells in vitro or in vivo.

Multiple endocrine neoplasia type 1 syndrome (MEN1, MIM 131100), an autosomal dominant disease, is characterized by parathyroid hyperplasia, pancreatic endocrine tumors, and pituitary adenomas. These tumors also occur sporadically. Both the familial (MEN1) and the sporadic tumors reveal loss of heterozygosity (LOH) for chromosome band 11q13 sequences. Based on prior linkage and LOH analyses, the MEN1 gene was localized between PYGM and D11S460. Recently, the MEN1 gene (menin) has been cloned from sequences 30-kb distal to PYGM. We performed deletion mapping on 25 endocrine tumors (5 MEN1 and 20 sporadic) by using 21 polymorphic markers on chromosome band 11q13. Of these, two (137C7A, 137C7B) were derived from PYGM-containing BAC (bacterial artificial chromosome-137C7) sequences, one from INT2-containing cosmid sequences and the marker D11S4748, a (CA)20 repeat marker that was developed by us. The LOH analysis shows that the markers close to the MEN1 (menin) gene were not deleted in three of the tumors. These tumors, however, showed LOH for distal markers. Thus, the data suggest the existence of a second tumor suppressor gene on chromosome band 11q13. Genes Chromosomes Cancer 22:130–137, 1998. © 1998 Wiley-Liss, Inc.

Introduction. The purpose of this study was to determine whether the multiple tumor suppressor 2 (MTS2) gene, encoding an inhibitor (p15) of cyclin D-dependent kinases 4 and 6 (cdk4, cdk6), is deleted in head and neck squamous cell carcinomas (HNSCC). There is a high frequency of LOH for the 9p21–p22 region in HNSCCs, as well as in gliomas, leukemias, and cell lines from multiple tumor types; thus, this region is suspected to contain a tumor suppressor gene or genes. P16 (MTS1), an inhibitor of cdk4 and cdk6, resides within the deleted 9p21 region in these tumors. A neighboring gene, p15 (MTS2), has biochemical properties similar to those of p16, but has not been characterized in HNSCC. Methods. Twenty-one head and neck squamous cell carcinomas and their proximal margins were snap frozen at the time of surgical resection. DNA isolation was performed using standard phenol and chloroform extraction. Standard PCR methods were used with primers P15-1F and P15-1R, specific for exon 1 of the p15 gene, as described previously. All samples were amplified for β-Globin as a positive control. PCR products were stained with ethidium bromide and run on 6% polyacrylamide gels. Expected sizes for the PCR products were p15, 532 bp, and β-globin, 238 bp. Results. Of 21 proximal margins, all demonstrated normal amplification of p15 DNA, all having a visible 532bp PCR product. Of 21 HNSCC tumors, 9 showed no amplification of the p15 gene; none of these 9 neoplasms had visible PCR products. All proximal margins and head and neck squamous cell carcinomas demonstrated amplification of the β-globin gene, indicating that the DNA used was of good quality. Conclusions. Although PCR is not a quantitative technique, densitometric analysis of PCR products showed it was unlikely that the p15 gene was present in more than a small fraction of the tumor cells. The amount of the p15 PCR product in these cells was less than 3% of that observed in reactions containing an equal amount of DNA from normal cells. We are the first to show an absence of normal p15 exon 1 gene amplification in nearly 50% of HNSCCs studied. Loss of the MTS2 gene product, p15, may contribute to the loss of cell cycle and growth regulation seen in HNSCC.

A transcription map of a 1200-kb region encompassing the MEN1 locus was constructed by direct cDNA selection and mapping ESTs. A total of 29 genes were mapped. Ten transcripts were identified by cDNA selection of a focused 300-kb genomic region telomeric to the MEN1 consensus region. Since many of the sequences cloned by cDNA selection also identified ESTs from the region, 19 additional RH-mapped ESTs were mapped to the entire contig region by PCR amplification of genomic clones. Nine known genes, 2 putative human homologues to mouse genes, and 18 novel transcripts map to the region. Transcripts that map to the MEN1 interval PYGM –D11S449 include SGC35223, IB1256, AA147620, ZFM1, FAU, and CAPN1. The latter 3 known genes have already been excluded as candidate MEN1 genes. The 2 putative human homologues of mouse genes Ltbp2 and Spa-1 may be candidate tumor suppressor genes, but they map telomeric to D11S449. Although both of these genes map outside the MEN1 consensus region they may play a role in sporadic endocrine tumors independent of the MEN1 gene or in other tumors, such as breast cancer, that have loss of heterozygosity within this region.

Linkage analysis and loss of heterozygosity studies have shown that the gene responsible for the multiple endocrine neoplasia type-1 (MEN1) syndrome localizes to a small interval between D11S427 and D11S460 on chromosome 11q13. As an initial step to clone this tumor suppressor gene, our group is the first to map the MEN1 region physically using yeast artificial chromosome, bacterial artificial chromosome (BAC), and cosmid contigs. The 1.5-Mb high-resolution, contiguous map extends from PYGM to 300 kb telomeric of D11S460. Of this, the 1.2-Mb interval between PYGM and D11S460 is isolated in cosmids and BACs and will be useful for the development of genomic sequences and transcription maps of this important region. Nine new sequence-tagged sites (STS) are also characterized from this region. The physical map and the STSs will be valuable tools for the cloning of the MEN1 gene.

Embryonic stem cells divide continuously and differentiate into organs through the expression of specific transcription factors at specific time periods. Differentiated adult stem cells on the other hand remain in quiescent state and divide by receiving cues from the environment (extracellular matrix or niche), as in the case of wound healing from tissue injury or inflammation. Similarly, it is believed that cancer stem cells (CSCs), forming a smaller fraction of the tumor bulk, also remain in a quiescent state. These cells are capable of initiating and propagating neoplastic growth upon receiving environmental cues, such as overexpression of growth factors, cytokines, and chemokines. Candidate CSCs express distinct biomarkers that can be utilized for their identification and isolation. This review focuses on the known and candidate cancer stem cell markers identified in various solid tumors and the promising future of disease management and therapy targeted at these markers. The review also provides details on the differential expression of microRNAs (miRNAs), and the miRNA- and natural product-based therapies that could be applied for the treatment of cancer stem cells.

Previous experiments have shown that curcumin or cisplatin treatment suppresses growth of head and neck squamous cell carcinoma (HNSCC). To study the potential cooperative effect of both agents, two HNSCC cell lines were treated with curcumin or cisplatin alone or in combination. In vivo studies consisted of intravenous tail vein injection of liposomal curcumin, with intraperitoneal cisplatin, into nude mice growing xenograft HNSCC tumors. Introduction of curcumin and suboptimal concentrations of cisplatin showed a significant suppressive effect compared with treatment with either agent alone. Reduced expression of cyclin D1, IκBα, phospho-IκBα, and IKKβ occurred in cisplatin- and curcumin-treated cell lines. Confocal microscopy showed expression of IKKβ in the nucleus of the cell lines. Chromatin immunoprecipitation assay on DNA isolated from IKKβ immunoprecipitated samples showed PCR amplification of interleukin-8 promoter sequences, a binding site of NFκB, indicating an interaction between IKKβ and NFκB. Curcumin inhibited IKKβ in the cytoplasm and nucleus, leading to reduced NFκB activity, with no effect on phospho-AKT. In vivo studies showed significant growth inhibition of xenograft tumors treated with a combination of liposomal curcumin and cisplatin. The suppressive effect of curcumin was mediated through inhibition of cytoplasmic and nuclear IKKβ, resulting in inhibition of NFκB activity. Cisplatin treatment led to cellular senescence, indicating an effect mediated by p53 activation. The mechanisms of the two agents through different growth signaling pathways suggest potential for the clinical use of subtherapeutic doses of cisplatin in combination with curcumin, which will allow effective suppression of tumor growth while minimizing the toxic side effects of cisplatin. Mol Cancer Ther; 9(10); 2665–75. ©2010 AACR.

To evaluate the effect of curcumin on production of interleukin 6 (IL-6) and 8 (IL-8) in head and neck squamous cell carcinoma (HNSCC) cell lines and to determine the mechanism by which these effects are modulated. Curcumin suppression of HNSCC is believed to be partly due to inhibition of the transcription factor nuclear factor-kappa beta (NF-kappa beta). Interleukin 6 and IL-8 are cytokines induced by NF-kappa beta activation with elevated levels in the serum of patients with HNSCC.We treated HNSCC cell lines CCL23, CAL27, UM-SCC1, and UM-SCC14A with increasing doses of curcumin and measured IL-6 and IL-8 levels using an enzyme-linked immunosorbent assay.Levels of NF-kappa beta, Ikappa beta kinase (IKK), and phosphorylated Ikappa beta were analyzed by means of Western blot. The IKK activity was measured in UM-SCC14A cells using an IKK-specific Ikappa beta alpha substrate after treatment with curcumin.Reverse transcription-polymerase chain reaction was performed to determine the effect of curcumin on the expression of IL-6 and IL-8.Curcumin treatment resulted in dose-dependent inhibition of IL-6 and IL-8 in all cell lines. All cell lines had similar NF-kappa beta levels; however, UM-SCC1 and UM-SCC14A had significantly higher Ikappa beta kinase levels and required considerably higher doses of curcumin before inhibition of IL-6 and IL-8 occurred. Curcumin treatment resulted in inhibition of IKK activity and inhibition of IL-6 and IL-8 expression.Curcumin significantly reduces IL-6 and IL-8 levels in HNSCC cell lines. This mechanism appears to be mediated via inhibition of Ikappa beta-kinase activity in the NF-kappa beta pathway. Interleukins 6 and 8 have potential use as biomarkers to measure the efficacy of treatment with curcumin.

Purpose: The purpose of this study was to determine whether a liposomal formulation of curcumin would suppress the growth of head and neck squamous cell carcinoma (HNSCC) cell lines CAL27 and UM-SCC1 in vitro and in vivo.Experimental Design: HNSCC cell lines were treated with liposomal curcumin at different doses and assayed for in vitro growth suppression using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. A reporter gene assay was done on cell lines to study the effect of liposomal curcumin on nuclear factor κB (NFκB) activation. Western blot analysis was done to determine the effect of curcumin on the expression of NFκB, phospho-IκBα, phospho-AKT (pAKT), phospho-S6 kinase, cyclin D1, cyclooxygenase-2, matrix metalloproteinase-9, Bcl-2, Bcl-xL, Mcl-1L, and Mcl-1S. Xenograft mouse tumors were grown and treated with intravenous liposomal curcumin. After 5 weeks, tumors were harvested and weighed. Immunohistochemistry and Western blot analyses were used to study the effect of liposomal curcumin on the expression of NFκB and pAKT.Results: The addition of liposomal curcumin resulted in a dose-dependent growth suppression of both cell lines. Liposomal curcumin treatment suppressed the activation of NFκB without affecting the expression of pAKT or its downstream target phospho-S6 kinase. Expression of cyclin D1, cyclooxygenase-2, matrix metalloproteinase-9, Bcl-2, Bcl-xL, Mcl-1L, and Mcl-1S were reduced, indicating the effect of curcumin on the NFκB pathway. Nude mice xenograft tumors were suppressed after 3.5 weeks of treatment with i.v. liposomal curcumin, and there was no demonstrable toxicity of liposomal curcumin upon autopsy. Immunohistochemistry and Western blot analysis on xenograft tumors showed the inhibition of NFκB without affecting the expression of pAKT.Conclusions: Liposomal curcumin suppresses HNSCC growth in vitro and in vivo. The results suggest that liposomal curcumin is a viable nontoxic therapeutic agent for HNSCC that may work via an AKT-independent pathway.

We have previously localized a cervical cancer tumor suppressor gene to a 300 kb interval of 11q13. Analysis of candidate genes revealed loss of expression of cystatin E/M, a lysosomal cysteine protease inhibitor, in 6 cervical cancer cell lines and 9 of 11 primary cervical tumors. Examination of the three exons in four cervical cancer cell lines, 19 primary tumors, and 21 normal controls revealed homozygous deletion of exon 1 sequences in one tumor. Point mutations were observed in six other tumors. Two tumors contained mutations at the consensus binding sites for cathepsin L, a lysosomal protease over-expressed in cervical cancer. Introduction of these two point mutations using site directed mutagenesis resulted in reduced binding of mutated cystatin E/M to cathepsin L. Although mutations were not observed in any cell lines, four cell lines and 12 of 18 tumors contained promoter hypermethylation. Re-expression of cystatin E/M was observed after 5′aza 2-deoxycytidiene and/or Trichostatin A treatment of cervical cancer cell lines, HeLa and SiHa, confirming promoter hypermethylation. Ectopic expression of cystatin E/M in these two cell lines resulted in growth suppression. There was also suppression of soft agar colony formation by HeLa cells expressing the cystatin E/M gene. Re-expression of cystatin E/M resulted in decreased intracellular and extracellular expression of cathepsin L. Over-expression of cathepsin L resulted in increased cell growth which was inhibited by the reintroduction of cystatin E/M. We conclude, therefore, that cystatin E/M is a cervical cancer suppressor gene and that the gene is inactivated by somatic mutations and promoter hypermethylation.