A pilot study of longitudinal serum cytokine and angiogenesis factor levels as markers of therapeutic response and survival in patients with head and neck squamous cell carcinoma

The Role of the NF-kappaB Transcriptome and Proteome as Biomarkers in Human Head and Neck Squamous Cell Carcinomas

NF-kappaB is a family of signal activated transcription factors comprised of hetero- or homo-dimers from 5 different subunits, NF-kappaB1, NF-kappaB2, RELA, cREL and RELB. NF-kappaBs normally are transiently activated in response to infection or injury, but in cancers are aberrantly activated, regulating a transcriptome of hundreds of genes and corresponding proteome that promote pathogenesis and therapeutic resistance. In head and neck squamous cell carcinomas, an important role of NF-kappaB in regulation of the altered transcriptome and proteome has been established, providing a catalog of activating and target genes and proteins that may be useful as biomarkers of alterations in this pathway for this and other cancers. An emerging appreciation that NF-kappaB and other signal pathways form an altered regulatory network highlights the need to use biomarkers and combine targeted agents for personalized therapy of cancer.

Targeting angiogenesis in head and neck cancer

Tumor angiogenesis is a hallmark of advanced cancers and an attractive treatment target in multiple solid tumors. In the past 5 years anti-angiogenic therapies have seen a rapid ascent into mainstream clinical practice. For head and neck cancer (HNC), definitive evidence in the form of a pivotal trial is still pending. Nevertheless, preclinical and early clinical data support a central role of angiogenesis for HNC: up to 90% of HNCs express angiogenic factors such as vascular endothelial growth factor (VEGF) and the respective receptors (VEGFR1-3), and multiple studies support the prognostic implications of angiogenic markers for this tumor. Contrary to concerns that anti-angiogenic therapies could increase hypoxia and thereby treatment resistance, anti-angiogenic therapies in preclinical models appear to overcome resistance and preclinically synergize with traditional therapies, eg, radiation. Clinical use of anti-angiogenic agents for HNC, including bevacizumab, sorafenib, sunitinib, and others, is currently limited to clinical trials, and several larger trials are still ongoing. Single-agent anti-angiogenic drugs so far have not shown activity in unselected HNC patients, with a response rate of less than 4% for the small molecule anti-angiogenics sorafenib and the investigational agent SU5416. On the other hand, combinations of anti-angiogenic drugs with other treatments (analogous to other solid tumors) appear promising; for example, the combination of bevacizumab with the EGFR inhibitor erlotinib showed a response rate of 14.6%. Studies of bevacizumab with chemotherapy (phase III Eastern Cooperative Oncology Group [ECOG] trial) and in combination with chemoradiation are currently ongoing. The side effect profile is comparable to what has been observed in other tumor types and include hypertension, proteinuria, and thrombotic and hemorrhagic events. With the intense research effort preclinically and clinically, and some encouraging early results, anti-angiogenic therapies and biomarkers appear to be poised to play an important role in the treatment of HNC in the near future.

Phase II trial of irinotecan plus cisplatin in patients with recurrent or metastatic squamous carcinoma of the head and neck

BACKGROUND

Patients with recurrent or metastatic HNC have a poor response and survival with currently available chemotherapy agents. Thus, new agents are needed. The authors report the results of a phase II trial of irinotecan and cisplatin in patients with metastatic or recurrent HNC.

METHODS

Patients were treated with irinotecan 65 mg/m2 IV over 90 minutes and cisplatin 30 mg/m2 were administered intravenously weekly for four weeks, followed by a two week rest. However, after 17 patients were treated with weekly irinotecan at a dose of 65 mg/m2, toxicity analysis demonstrated the poor tolerance of that dose in this patient population. Thus, the protocol was amended, and irinotecan was dose reduced to a starting dose of 50 mg/m2. Twenty-three additional patients were treated with this dose.

RESULTS

Forty patients were enrolled on study between February 2002 and April 2006, 17 patients at the first dose level and 23 patients at the amended dose level. Overall, 12 of 17 patients (71%) treated with irinotecan 65 mg/m2 experienced clinically significant grade 3 or 4 toxicity. Twelve patients required dose reductions. Toxicity was reduced but 17% of patients still experienced grade 3 or 4 toxicity on the lower irinotecan dose. The response rate was 35% for patients treated at irinotecan 65 mg/m2 and 22% for patients treated at 50 mg/m2. No complete responses were noted.

CONCLUSIONS

The combination of irinotecan and cisplatin is efficacious in a poor prognosis group of patients but toxicity is substantial.

Daily low-dose/continuous capecitabine combined with neo-adjuvant irradiation reduces VEGF and PDGF-BB levels in rectal carcinoma patients

Metronomic low-dose chemotherapy regimen was found to have an antiangiogenic effect in tumors. However, its effect on levels of circulating pro-angiogenic and anti-angiogenic factors is not fully explored.

MATERIALS AND METHODS

The levels of both VEGF and PDGF-BB were measured in three time points, in the serum of 32 rectal carcinoma patients receiving daily reduced-dose/continuous capecitabine in combination with preoperative pelvic irradiation.

RESULTS

We found a significant decrease in VEGF and PDGF-BB serum levels during the combination treatment (p < 0.0001), followed by an increase in the successive rest-period (p < 0.0001). In addition, substantial changes in platelets counts were observed during treatment in correlation with the changes of VEGF and PDGF-BB serum levels.

DISCUSSION

These results suggest that combined chemo-irradiation affect levels of pro-angiogenic factors during treatment, and may reflect an anti-angiogenic window induced during this treatment. The potential implications of this inducible phenomenon, including a possible clinical benefit from the administration of long lasting metronomic chemotherapy immediately following combined chemo-irradiation, would warrant further investigation.

Differential bortezomib sensitivity in head and neck cancer lines corresponds to proteasome, nuclear factor-kappaB and activator protein-1 related mechanisms

Head and neck squamous cell carcinomas (HNSCC) exhibit constitutive activation of transcription factors nuclear factor-kappaB (NF-kappaB) and activator protein-1 (AP-1), which are modulated by the proteasome and promote resistance to cell death. HNSCC show variable sensitivity to the proteasome inhibitor bortezomib in vitro as well as in murine xenografts and patient tumors in vivo, and the mechanisms are not well understood. To address this question, the sensitivities of nine HNSCC cell lines to bortezomib were determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays, and the potential relationship between the sensitivity and bortezomib effects on biological processes was examined in HNSCC lines of differential bortezomib sensitivity. The most sensitive cell line (UM-SCC-11B) underwent cell death at 10(-9) mol/L in vitro and tumor regression at a maximally tolerated dose of bortezomib in a murine xenograft model. The differential sensitivity between UM-SCC-11A and UM-SCC-11B cells corresponded to differences in the extent of suppression of proteasome activity, ubiquitinated protein degradation, and NF-kappaB and AP-1 activation. Lower concentrations of bortezomib transiently increased NF-kappaB and sustained AP-1 activation in UM-SCC-11A cells. AP-1 reporter activity and cell density of UM-SCC-11A were suppressed when bortezomib was combined with c-Jun NH(2)-terminal kinase and p38 kinase pathways inhibitors. Thus, the differential sensitivities to bortezomib corresponded to dissimilar effects on the proteasome, NF-kappaB and AP-1 activities. Inhibition of c-Jun NH(2)-terminal kinase and p38 pathways blocked AP-1 activity and enhanced the antitumor effects. These findings revealed molecular mechanisms of bortezomib sensitivity and resistance, which are under development as biomarkers for clinical trials in patients with HNSCC.

Phase I Study of Bevacizumab Added to Fluorouracil- and Hydroxyurea-Based Concomitant Chemoradiotherapy for Poor-Prognosis Head and Neck Cancer

Purpose

We conducted a phase I dose escalation study to determine the maximum-tolerated dose (MTD) and dose-limiting toxicity (DLT) of bevacizumab, when added to the standard FHX (fluorouracil [FU], hydroxyurea [HU], radiation) chemoradiotherapy platform in poor-prognosis head and neck cancer (HNC) patients.

Patients and Methods

Patients with recurrent, previously radiated or poor-prognosis, treatment-naive HNC were eligible. Treatment was repeated every 14 days for seven cycles: Bevacizumab was escalated 2.5 to 10 mg/kg, FU 600 to 800 mg/m2(120 hours continuous infusion), and hydroxyurea from 500 to 1,000 mg (twice daily for 5 days), starting day 1. At the MTD, the cohort was expanded.

Results

Forty-three patients were treated. DLT was reached at level 3 (bevacizumab 5 mg/kg, FU 800 mg/m2, HU 1,000 mg) with two grade 3 transaminase elevations and one grade 4 neutropenia, attributed to the combination of chemotherapy with bevacizumab. For level 4, chemotherapy doses were reduced (FU 600 mg/2, HU 500 mg), and bevacizumab escalation continued to 10 mg/kg. Treatment of six assessable patients resulted in one venous thrombosis; this dose level was expanded to 26 patients. Late complications included five patients with fistula formation (11.6%) and four with ulceration/tissue necrosis (9.3%). Serious toxicities (hemorrhage/thrombosis/death) were comparable to prior reirradiation reports. Median overall survival for reirradiated patients with recurrent, nonmetastatic disease was 10.3 months [95% CI, 5.6 to 13.5]; 2-year cumulative incidence of death resulting from disease was 51.7% (95% CI, 31.7 to 68.5).

Conclusion

Bevacizumab can be integrated with FHX chemoradiotherapy at a dose of 10 mg/m2every 2 weeks with decreased chemotherapy doses because of neutropenia. The regimen shows antitumor activity. Observed fistula formation/tissue necrosis may be bevacizumab related, and further investigation should proceed with careful monitoring.

Systems biology-defined NF-kappaB regulons, interacting signal pathways and networks are implicated in the malignant phenotype of head and neck cancer cell lines differing in p53 status

BACKGROUND

Aberrant activation of the nuclear factor kappaB (NF-kappaB) pathway has been previously implicated as a crucial signal promoting tumorigenesis. However, how NF-kappaB acts as a key regulatory node to modulate global gene expression, and contributes to the malignant heterogeneity of head and neck cancer, is not well understood.

RESULTS

To address this question, we used a newly developed computational strategy, COGRIM (Clustering Of Gene Regulons using Integrated Modeling), to identify NF-kappaB regulons (a set of genes under regulation of the same transcription factor) for 1,265 genes differentially expressed by head and neck cancer cell lines differing in p53 status. There were 748 NF-kappaB targets predicted and individually annotated for RELA, NFkappaB1 or cREL regulation, and a prevalence of RELA related genes was observed in over-expressed clusters in a tumor subset. Using Ingenuity Pathway Analysis, the NF-kappaB targets were reverse-engineered into annotated signature networks and pathways, revealing relationships broadly altered in cancer lines (activated proinflammatory and down-regulated Wnt/beta-catenin and transforming growth factor-beta pathways), or specifically defective in cancer subsets (growth factors, cytokines, integrins, receptors and intermediate kinases). Representatives of predicted NF-kappaB target genes were experimentally validated through modulation by tumor necrosis factor-alpha or small interfering RNA for RELA or NFkappaB1.

CONCLUSION

NF-kappaB globally regulates diverse gene programs that are organized in signal networks and pathways differing in cancer subsets with distinct p53 status. The concerted alterations in gene expression patterns reflect cross-talk among NF-kappaB and other pathways, which may provide a basis for molecular classifications and targeted therapeutics for heterogeneous subsets of head and neck or other cancers.

Role of activated nuclear factor-kappaB in the pathogenesis and therapy of squamous cell carcinoma of the head and neck

BACKGROUND

Nuclear factor-kappaB (NF-kappaB), a transcription factor known to modulate expression of factors involved in inflammation, immunity, proliferation, and apoptosis, is constitutively activated and plays a role in pathogenesis and therapeutic resistance in head and neck squamous cell carcinoma (HNSCC). Understanding the molecular alterations leading to aberrant NF-kappaB activation in HNSCC may direct investigators to novel therapeutic targets.

METHODS

Results of laboratory and clinical studies are reviewed.

RESULTS

The structure, function, and activation of NF-kappaB, products of NF-kappaB target genes and their role in HNSCC oncogenesis, and current NF-kappaB modulating interventions are described.

CONCLUSIONS

Aberrant NF-kappaB activation contributes to the expression of oncogenes and the malignant phenotype observed in HNSCC. NF-kappaB, along with providing a link between cancer and inflammation, may serve as an appropriate therapeutic target to inhibit tumor growth and sensitize cancer cells to established cytotoxic anticancer therapies.

A novel nuclear factor-kappaB gene signature is differentially expressed in head and neck squamous cell carcinomas in association with TP53 status

PURPOSE

To determine if gene signatures differentially expressed in head and neck squamous cell carcinomas (HNSCC) are related to alterations in transcription factors nuclear factor-kappaB (NF-kappaB) and TP53 previously associated with decreased cell death, response to therapy, and worse prognosis.

EXPERIMENTAL DESIGN

Unique gene signatures expressed by HNSCC lines were identified by cDNA microarray, principal components, and cluster analyses and validated by quantitative reverse transcription-PCR (RT-PCR) and in situ hybridization. Bioinformatic analysis of the promoters and ontogeny of these clustered genes was done. Expression of proteins encoded by genes of a putative NF-kappaB signature, NF-kappaB p65, and TP53 were examined in HNSCC tissue specimens by immunostaining. Predicted promoter binding and modulation of expression of candidate NF-kappaB genes and cell survival were evaluated by p65 chromatin immunoprecipitation (ChIP) and small interfering RNA (siRNA) knockdown.

RESULTS

Two groups of HNSCC exhibiting distinct gene signatures were identified: cluster A enriched for histone genes, with a higher prevalence of TP53 promoter binding motifs; and cluster B enriched for injury response genes with NF-kappaB regulatory motifs. Coexpression of cluster B proteins was observed with strong NF-kappaB phospho-p65 and weak TP53 staining, and NF-kappaB phospho-p65 was inversely associated with TP53 (P = 0.02). Promoter binding of the NF-kappaB signature genes was confirmed by p65 ChIP, and down-modulation of their expression and cell death were induced by p65 siRNA.

CONCLUSION

NF-kappaB promotes expression of a novel NF-kappaB-related gene signature and cell survival in HNSCC that weakly express TP53, a subset previously associated with inactivated wild-type TP53, greater resistance to chemoradiotherapy, and worse prognosis.

Serum hepatocyte growth factor as a marker of tumor activity in head and neck squamous cell carcinoma

Hepatocyte growth factor (HGF) has previously been reported to be elevated in the serum of patients with malignancy, including breast, colorectal and gastric cancers. Here, we evaluated the correlation between serum HGF and the progression of head and neck squamous cell carcinoma (HNSCC). The mean serum HGF levels in 71 healthy control subjects, 78 patients with primary HNSCC, and eight patients with recurrent HNSCC were 0.538+/-0.163, 0.701+/-0.252, and 0.925+/-0.349ng/ml, respectively. The increase in the HGF level was significantly correlated with tumor stage progression. The HGF level had decreased to normal at 1 month after curative resection of the tumors. During follow-up for several months, the HGF level significantly increased in recurrent HNSCC patients, whereas there was no increase in nonrecurrent patients. Our data suggest that serum HGF is significantly corrected with tumor progression and may be a strong predictor of recurrence in HNSCC.

Changes in body mass, energy balance, physical function, and inflammatory state in patients with locally advanced head and neck cancer treated with concurrent chemoradiation after low-dose induction chemotherapy

BACKGROUND

We aimed to determine changes in body mass and body composition in relation to energy balance, inflammatory state, and physical function before and after concurrent chemoradiation (CCR).

METHODS

Seventeen patients with stage III and IVa head and neck cancer, aged 58.9 +/- 5.4 years, who had completed a 9-week regimen of low-dose induction chemotherapy came to the General Clinical Research Center pre- and post-CCR for measurement of body mass composition by dual-energy X-ray absorptiometry, resting energy expenditure (REE) by indirect calorimetry, physical performance (by Modified Baecke Questionnaire and Reuben's Physical Performance Test), and functionality (Activities and Instrumental Activities of Daily Living scores). Fasting venous samples were collected to determine C-reactive protein and cytokines interleukin (IL)-1beta, IL-6, IL-8, and IL-10. Random 24-hour telephone diet recalls assessed energy intakes.

RESULTS

Weight loss began 1 week after CCR. Lean body mass (LBM) accounted for 71.7% +/- 21% of body mass loss. No change occurred in energy intakes or calorie/nitrogen ratio. REE was significantly increased when adjusted for LBM loss (kcal/kg), p = .019. LBM loss was significantly associated with physical performance decline, r = .71, p = .004, and increased functional dependence, r = .58, p = .02. Total physical activity level declined significantly, p = .003. Cytokine levels were strongly associated with physical and functional decline.

CONCLUSIONS

The aberrant changes in body composition, metabolism, and inflammatory state were associated with clinically and statistically significant impairments in physical performance and function. Future investigations and clinical practice should combine nutrition with antiinflammatory agents and exercise activities to support lean tissue anabolism and prevent physical and functional decline of patients with head and neck cancer undergoing CCR.

The potential role of intrinsic hypoxia markers as prognostic variables in cancer

Tumor hypoxia is related to tumor progression and therapy resistance, which leads to poor patient outcome. It has been suggested that measuring the hypoxic status of a tumor helps to predict patient outcome and to select more targeted treatment. However, current methods using needle electrodes or exogenous markers have limitations due to their invasiveness or necessity for preinjection. Recent studies showed that hypoxia-regulated genes could be alternatively used as endogenous hypoxia markers. This is a review of 15 hypoxia-regulated genes, including hypoxia-inducible factor-1 and its targets, and their correlation with tumor hypoxia and patient outcome from 213 studies. Though most of the studies showed significance of these genes in predicting prognosis, there was no definitive prognostic and hypoxia marker. In conclusion, this review suggests the need for further studies with standardized methods to examine gene expression, as well as the use of multiple gene expressions.

Associations of circulating C-reactive protein and interleukin-6 with survival in women with and without cancer: findings from the British Women's Heart and Health Study

BACKGROUND

Inflammation is associated with worse prognosis and survival in many cancers. Our aim was to investigate the associations of circulating C-reactive protein (CRP) and interleukin-6 (IL-6) concentrations with all-cause mortality in cancer patients and to determine whether any associations were specific to malignancy.

METHOD

We used data from the British Women's Heart and Health Study, a cohort of 4,286 women aged 60 to 79 years. We investigated the associations between CRP, IL-6, and survival in women with and without cancer using Cox regression and assessed the interaction between cancer status and these inflammatory markers to determine whether these associations differed according to cancer status.

RESULTS

Elevated CRP and IL-6 were associated with decreased survival in women with cancer [unadjusted hazard ratio per doubling of CRP, 1.22, 95% confidence interval (95% CI), 1.03, 1.46; and per doubling of IL-6, 1.52, 95% CI, 1.25, 1.86] and in women without cancer [CRP: 1.24 (1.12, 1.37); IL-6: 1.53 (1.35, 1.75)]. Adjustment for age, body mass index, physical activity level, socioeconomic position, HRT use, and tobacco smoking did not change these associations. After mutual adjustment, IL-6 but not CRP was independently associated with survival. We found no strong evidence that these associations differed between cancer patients and cancer-free women.

CONCLUSIONS

Elevated CRP and IL-6 concentrations were similarly associated with an increased risk of death in elderly women with and without cancer. Thus, in this group, these markers are likely to be indicators of non-cancer comorbidities rather than related to the malignancy itself.

Nuclear Factor-κB–Related Serum Factors as Longitudinal Biomarkers of Response and Survival in Advanced Oropharyngeal Carcinoma

PURPOSE

Cytokines and growth factors modulated by transcription factor nuclear factor-kappaB and secreted by tumor and stromal cells are detectable in serum of patients with advanced cancers, including head and neck squamous cell carcinomas (SCC). Longitudinal changes in these serum factors could be early biomarkers of treatment response and survival.

EXPERIMENTAL DESIGN

Interleukin (IL)-6, IL-8, growth-related oncogene-1 (GRO-1), vascular endothelial growth factor (VEGF), and hepatocyte growth factor (HGF) concentrations were determined by Luminex multiplex assay using serum obtained at baseline and every 3 months in a prospective study of 30 patients with locally advanced (stage III/IV) oropharyngeal SCC receiving chemoradiation therapy. The relationship between baseline and direction of change in individual and multiple cytokines with cause-specific and disease-free survival was determined by Cox proportional hazards models and Kaplan-Meier survival analysis. Statistical analyses included adjustment for smoking status and response to chemoradiation.

RESULTS

Three-year cause-specific and disease-free survival was 74.4% and 68.9%. Nonsmoking history (P = 0.05) and higher baseline VEGF (P = 0.003) correlated with increased survival. Longitudinal increases in levels of individual factors predicted decreased cause-specific survival when adjusted for smoking history [IL-6: relative risk (RR), 3.8; 95% confidence interval (95% CI), 2.0-7.4; P = 0.004; IL-8: RR, 1.6; 95% CI, 1.2-2.2; P = 0.05; VEGF: RR, 3.0; 95% CI, 1.6-5.6; P = 0.01; HGF: RR, 2.9; 95% CI, 1.9-4.4; P = 0.02; and GRO-1: RR, 1.2; 95% CI, 1.1-1.3; P = 0.02]. For a given individual, large increases in the upper quartile for any three or more factors predicted poorer cause-specific survival compared with patients with two or fewer large increases in factor levels (P = 0.004).

CONCLUSIONS

Pretreatment VEGF levels and longitudinal change in IL-6, IL-8, VEGF, HGF, and GRO-1 may be useful as biomarkers for response and survival in patients with locally advanced oropharyngeal and head and neck SCC treated with chemoradiation.

Early Detection of Head and Neck Cancer: Development of a Novel Screening Tool Using Multiplexed Immunobead-Based Biomarker Profiling

Squamous cell carcinoma of the head and neck (SCCHN) is an aggressive disease that has been linked to altered immune, inflammatory, and angiogenesis responses. A better understanding of these aberrant responses might improve early detection and prognosis of SCCHN and provide novel therapeutic targets. Previous studies examined the role of multiplexed serum biomarkers in small cohorts or SCCHN sera. We hypothesized that an expanded panel comprised of multiple cytokines, chemokines, growth factors, and other tumor markers, which individually may show some promising correlation with disease status, might provide higher diagnostic power if used in combination. Thus, we evaluated a novel multianalyte LabMAP profiling technology that allows simultaneous measurement of multiple serum biomarkers. Concentrations of 60 cytokines, growth factors, and tumor antigens were measured in the sera of 116 SCCHN patients before treatment (active disease group), 103 patients who were successfully treated (no evidence of disease group), and 117 smoker controls without evidence of cancer. The multimarker panel offering the highest diagnostic power was comprised of 25 biomarkers, including epidermal growth factor, epidermal growth factor receptor, interleukin (IL)-8, tissue plasminogen activator inhibitor-1, alpha-fetoprotein, matrix metalloproteinase-2, matrix metalloproteinase-3, IFN-alpha, IFN-gamma, IFN-inducible protein-10, regulated on activation, normal T-cell expressed and secreted (RANTES), macrophage inflammatory protein-1alpha, IL-7, IL-17, IL-1 receptor-alpha, IL-2 receptor, granulocyte colony-stimulating factor, mesothelin, insulin-like growth factor binding protein 1, E-selectin, cytokeratin-19, vascular cell adhesion molecule, and cancer antigen-125. Statistical analysis using an ADE algorithm resulted in a sensitivity of 84.5%, specificity of 98%, and 92% of patients in the active disease group correctly classified from a cross-validation serum set. The data presented show that simultaneous testing using a multiplexed panel of serum biomarkers may present a promising new approach for the early detection of head and neck cancer.

Aberrant cytokine expression in serum of patients with adenoid cystic carcinoma and squamous cell carcinoma of the head and neck

BACKGROUND

Squamous cell carcinoma (SCC) and adenoid cystic carcinoma (ACC) represent 2 clinically important subtypes of head and neck cancer. Our objective was to characterize and compare cytokine profiles in the systemic circulation of patients with SCC and ACC.

METHODS

Multiplex analysis of 10 different cytokines (interleukin [IL]-1beta, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, granulocyte-macrophage colony-stimulating factor [GM-CSF], interferon [IFN]-gamma, and tumor necrosis factor [TNF]-alpha) in the serum of patients with SCC (n = 20) and ACC (n = 20) and healthy controls (n = 20) was performed using the Luminex fluorescent-bead technology.

RESULTS

Patients with SCC as well as patients with ACC showed an altered cytokine profile compared with healthy individuals. In patients with SCC, significantly elevated serum levels of the proinflammatory cytokines, IL-6 and IL-8, were observed. In patients with ACC, IL-8 serum levels were significantly elevated, and IL-6 serum levels were only increased in a subset of patients.

CONCLUSIONS

A similar serum cytokine profile, with the predominance of proinflammatory cytokines, was observed in patients with SCC and ACC. The newly defined cytokine profile in ACC patients may form the basis for future investigations to explore the role of cytokines in ACC tumor progression and their potential value as predictive biomarkers.

Epigenetic modification of SOCS-1 differentially regulates STAT3 activation in response to interleukin-6 receptor and epidermal growth factor receptor signaling through JAK and/or MEK in head and neck squamous cell carcinomas

Signal transducer and activator of transcription 3 (STAT3) has been reported to be activated by interleukin-6 receptor (IL-6R) or epidermal growth factor receptor (EGFR) in head and neck squamous cell carcinomas (HNSCC), which may have important implications for responsiveness to therapeutics targeted at EGFR, IL-6R, or intermediary kinases. Suppressor of cytokine signaling-1 (SOCS-1) has been implicated recently in the negative regulation of IL-6R/Janus-activated kinase (JAK)-mediated activation of STAT3, suggesting that SOCS-1 could affect alternative activation of STAT3 by EGFR, IL-6R, and associated kinases. We investigated whether epigenetic modification of SOCS-1 affects STAT3 activation in response to IL-6R-, EGFR-, JAK-, or mitogen-activated protein kinase/extracellular signal-regulated kinase kinase (MEK)-mediated signal activation. STAT3 was predominantly activated by IL-6R via Jak1/Jak2 in HNSCC lines UMSCC-9 and UMSCC-38 in association with transcriptional silencing of SOCS-1 by hypermethylation. In UMSCC-11A cells with unmethylated SOCS-1, STAT3 activation was regulated by both EGFR and IL-6R via a JAK-independent pathway involving MEK. Pharmacologic inhibitors of JAK and MEK and expression of SOCS-1 following demethylation or transient transfection inhibited STAT3 activation and cell proliferation and induced cell apoptosis in corresponding cell lines. Hypermethylation of SOCS-1 was found in about one-third of human HNSCC tissues, making it a potentially relevant marker for STAT-targeted therapy in HNSCC patients. We conclude that SOCS-1 methylation status can differentially affect STAT3 activation by IL-6R and EGFR through JAK or MEK in different HNSCC and response to pharmacologic antagonists. Identifying the potential factors and the regulatory pathways in STAT3 activation has important implications for the development and selection of molecularly targeted therapy in HNSCC.