In vitro chemosensitivity of head and neck cancer cell lines

Modulating the unfolded protein response with ISRIB mitigates cisplatin ototoxicity

Cisplatin is a commonly used chemotherapy agent with a nearly universal side effect of sensorineural hearing loss. The cellular mechanisms underlying cisplatin ototoxicity are poorly understood. Efforts in drug development to prevent or reverse cisplatin ototoxicity have largely focused on pathways of oxidative stress and apoptosis. An effective treatment for cisplatin ototoxicity, sodium thiosulfate (STS), while beneficial when used in standard risk hepatoblastoma, is associated with reduced survival in disseminated pediatric malignancy, highlighting the need for more specific drugs without potential tumor protective effects. The unfolded protein response (UPR) and endoplasmic reticulum (ER) stress pathways have been shown to be involved in the pathogenesis of noise-induced hearing loss and cochlear synaptopathy in vivo, and these pathways have been implicated broadly in cisplatin cytotoxicity. This study sought to determine whether the UPR can be targeted to prevent cisplatin ototoxicity. Neonatal cochlear cultures and HEK cells were exposed to cisplatin, and UPR marker gene expression and cell death measured. Treatment with ISRIB (Integrated Stress Response InhIBitor), a drug that activates eif2B and downregulates the pro-apoptotic PERK/CHOP pathway of the UPR, was tested for its ability to reduce apoptosis in HEK cells, hair-cell death in cochlear cultures, and hearing loss using an in vivo mouse model of cisplatin ototoxicity. Finally, to evaluate whether ISRIB might interfere with cisplatin chemoeffectiveness, we tested it in head and neck squamous cell carcinoma (HNSCC) cell-based assays of cisplatin cytotoxicity. Cisplatin exhibited a biphasic, non-linear dose-response of cell death and apoptosis that correlated with different patterns of UPR marker gene expression in HEK cells and cochlear cultures. ISRIB treatment protected against cisplatin-induced hearing loss and hair-cell death, but did not impact cisplatin's cytotoxic effects on HNSCC cell viability, unlike STS. These findings demonstrate that targeting the pro-apoptotic PERK/CHOP pathway with ISRIB can mitigate cisplatin ototoxicity without reducing anti-cancer cell effects, suggesting that this may be a viable strategy for drug development.

Modulating the Unfolded Protein Response with ISRIB Mitigates Cisplatin Ototoxicity

Cisplatin is a commonly used chemotherapy agent with a nearly universal side effect of sensorineural hearing loss. The cellular mechanisms underlying cisplatin ototoxicity are poorly understood. Efforts in drug development to prevent or reverse cisplatin ototoxicity have largely focused on pathways of oxidative stress and apoptosis. An effective treatment for cisplatin ototoxicity, sodium thiosulfate (STS), while beneficial when used in standard risk hepatoblastoma, is associated with reduced survival in disseminated pediatric malignancies, highlighting the need for more specific drugs without potential tumor protective effects. The unfolded protein response (UPR) and endoplasmic reticulum (ER) stress pathways have been shown to be involved in the pathogenesis of noise-induced hearing loss and cochlear synaptopathy in vivo, and these pathways have been implicated broadly in cisplatin cytotoxicity. This study sought to determine whether the UPR can be targeted to prevent cisplatin ototoxicity. Neonatal cochlear cultures and HEK cells were exposed to cisplatin and UPR-modulating drugs, and UPR marker gene expression and cell death measured. Treatment with ISRIB, a drug that activates eif2B and downregulates the pro-apoptotic PERK/CHOP pathway of the UPR, was tested in an in vivo mouse model of cisplatin ototoxicity and well as a head and neck squamous cell carcinoma (HNSCC) cell-based assay of cisplatin cytotoxicity. Cisplatin exhibited a biphasic, non-linear dose-response of cell death and apoptosis that correlated with different patterns of UPR marker gene expression in HEK cells and cochlear cultures. ISRIB treatment protected against cisplatin-induced hearing loss and hair-cell death, but did not impact the cytotoxic effects of cisplatin on HNSCC cell viability, unlike STS. These findings demonstrate that targeting the pro-apoptotic PERK/CHOP pathway with ISRIB can mitigate cisplatin ototoxicity without reducing anti-cancer cell effects, suggesting that this may be a viable strategy for drug development.

Exposure to Secondhand Smoke Extract Increases Cisplatin Resistance in Head and Neck Cancer Cells

Chemotherapy and radiotherapy resistance are major obstacles in the long-term efficacy of head and neck squamous cell carcinoma (HNSCC) treatment. Secondhand smoke (SHS) exposure is common and has been proposed as an independent predictor of HNSCC recurrence and disease-free survival. However, the underlying mechanisms responsible for these negative patient outcomes are unknown. To assess the effects of SHS exposure on cisplatin efficacy in cancer cells, three distinct HNSCC cell lines were exposed to sidestream (SS) smoke, the main component of SHS, at concentrations mimicking the nicotine level seen in passive smokers' saliva and treated with cisplatin (0.01-100 µM) for 48 h. Compared to cisplatin treatment alone, cancer cells exposed to both cisplatin and SS smoke extract showed significantly lower cisplatin-induced cell death and higher cell viability, IC50, and indefinite survival capacity. However, SS smoke extract exposure alone did not change cancer cell viability, cell death, or cell proliferation compared to unexposed control cancer cells. Mechanistically, exposure to SS smoke extract significantly reduced the expression of cisplatin influx transporter CTR1, and increased the expression of multidrug-resistant proteins ABCG2 and ATP7A. Our study is the first to document that exposure to SHS can increase cisplatin resistance by altering the expression of several proteins involved in multidrug resistance, thus increasing the cells' capability to evade cisplatin-induced cell death. These findings emphasize the urgent need for clinicians to consider the potential role of SHS on treatment outcomes and to advise cancer patients and caregivers on the potential benefits of avoiding SHS exposure.

Microphysiological head and neck cancer model identifies novel role of lymphatically secreted monocyte migration inhibitory factor in cancer cell migration and metabolism

Regional metastasis of head and neck cancer (HNC) is prevalent (approximately 50% of patients at diagnosis), yet the underlying drivers and mechanisms of lymphatic spread remain unclear. The complex tumor microenvironment (TME) of HNC plays a crucial role in disease maintenance and progression; however, the contribution of the lymphatics remains underexplored. We created a primary patient cell derived microphysiological system that incorporates cancer-associated-fibroblasts from patients with HNC alongside a HNC tumor spheroid and a lymphatic microvessel to create an in vitro TME platform to investigate metastasis. Screening of soluble factor signaling identified novel secretion of macrophage migration inhibitory factor (MIF) by lymphatic endothelial cells conditioned in the TME. Importantly, we also observed patient-to-patient heterogeneity in cancer cell migration similar to the heterogeneity observed in clinical disease. Optical metabolic imaging at the single cell level identified a distinct metabolic profile of migratory versus non-migratory HNC cells in a microenvironment dependent manner. Additionally, we report a unique role of MIF in increasing HNC reliance on glycolysis over oxidative phosphorylation. This multicellular, microfluidic platform expands the tools available to explore HNC biology in vitro through multiple orthogonal outputs and establishes a system with enough resolution to visualize and quantify patient-to-patient heterogeneity.

The RNA-Binding Protein SMN as a Novel Player in Laryngeal Squamous Cell Carcinoma

Head and neck squamous cell carcinoma (HNSCC) arises from the mucosal epithelium in the oral cavity, pharynx, sino-nasal region, and larynx. Laryngeal squamous cell carcinoma (LSCC) represents one-third of all head and neck cancers. Dysregulated RNA-related pathways define an important molecular signature in this aggressive carcinoma. The Survival Motor Neuron (SMN) protein regulates fundamental aspects of the RNA metabolism but, curiously, its role in cancer is virtually unknown. For the first time, here, we focus on the SMN in the cancer context. We conducted a pilot study in a total of 20 patients with LSCC where the SMN was found overexpressed at both the protein and transcript levels. By a cellular model of human laryngeal carcinoma, we demonstrated that the SMN impacts cancer-relevant behaviors and perturbs key players of cell migration, invasion, and adhesion. Furthermore, in LSCC we showed a physical interaction between the SMN and the epidermal growth factor receptor (EGFR), whose overexpression is an important feature in these tumors. This study proposes the SMN protein as a novel therapeutic target in LSSC and likely in the whole spectrum of HNSCC. Overall, we provide the first analysis of the SMN in human cancer.

Differential effects of cisplatin combined with the flavonoid apigenin on HepG2, Hep3B, and Huh7 liver cancer cell lines

The potential of apigenin (APG) to enhance cisplatin's (CDDP) chemotherapeutic efficacy was investigated in HepG2, Hep3B, and Huh7 liver cancer cell lines. The presence of 20 μM APG sensitized all cell lines to CDDP treatment (degree of sensitization based on the MTT assay: HepG2>Huh7>Hep3B). As reflected by sister chromatid exchange levels, the degree of genetic instability as well as DNA repair by homologous recombination differed among cell lines. CDDP and 20 μM APG cotreatment exhibited a synergistic genotoxic effect on Hep3B cells and a less than additive effect on HepG2 and Huh7 cells. Cell cycle delays were noticed during the first mitotic division in Hep3B and Huh7 cells and the second mitotic division in HepG2 cells. CDDP and CDDP + APG treatments reduced the clonogenic capacity of all cell lines; however, there was a discordance in drug sensitivity compared with the MMT assay. Furthermore, a senescence-like phenotype was induced, especially in Hep3B and Huh7 cells. Unlike CDDP monotherapy, the combined treatment exhibited a significant anti-invasive and anti-migratory action in all cancer cell lines. The fact that the three liver cancer cell lines responded differently, yet positively, to CDDP + APG cotreatment could be attributed to variations they present in gene expression. Complex mechanisms seem to influence cellular responses and cell fate.

Diversity of dose-individualization and therapeutic drug monitoring practices of platinum compounds: a review

Introduction: Platinum-derived drugs are commonly used for the treatment of solid tumors. The differences in chemical structures of these molecules lead to different pharmacological properties, in terms of indication, efficacy, and toxicity. Their pharmacokinetics (PK) differ according to their respective renal elimination and have led to many studies investigating their dose optimization. Area covered: This review attempts to summarize and compare PK and pharmacodynamics of cisplatin, carboplatin, and oxaliplatin, with an emphasis on differences of dose calculations and opportunities for therapeutic drug monitoring (TDM) in various patient populations. Expert opinion: Although cisplatin and carboplatin can be considered as analogs since they share the same DNA interacting properties, the slower hydrolysis of the latter results in a better safety profile. Carboplatin is the only drug in oncology to be administrated according to a target area under the curve of concentration versus time, considering that its PK variability is almost fully explained by renal function, not by body size. This enables individual dosing based on predicted carboplatin clearance (along with patients renal characteristics) or on actual clearance with TDM, especially in a high-dose protocol.

Organic Cation Transporters in Health and Disease

The organic cation transporters (OCTs) OCT1, OCT2, OCT3, novel OCT (OCTN)1, OCTN2, multidrug and toxin exclusion (MATE)1, and MATE kidney-specific 2 are polyspecific transporters exhibiting broadly overlapping substrate selectivities. They transport organic cations, zwitterions, and some uncharged compounds and operate as facilitated diffusion systems and/or antiporters. OCTs are critically involved in intestinal absorption, hepatic uptake, and renal excretion of hydrophilic drugs. They modulate the distribution of endogenous compounds such as thiamine, L-carnitine, and neurotransmitters. Sites of expression and functions of OCTs have important impact on energy metabolism, pharmacokinetics, and toxicity of drugs, and on drug-drug interactions. In this work, an overview about the human OCTs is presented. Functional properties of human OCTs, including identified substrates and inhibitors of the individual transporters, are described. Sites of expression are compiled, and data on regulation of OCTs are presented. In addition, genetic variations of OCTs are listed, and data on their impact on transport, drug treatment, and diseases are reported. Moreover, recent data are summarized that indicate complex drug-drug interaction at OCTs, such as allosteric high-affinity inhibition of transport and substrate dependence of inhibitor efficacies. A hypothesis about the molecular mechanism of polyspecific substrate recognition by OCTs is presented that is based on functional studies and mutagenesis experiments in OCT1 and OCT2. This hypothesis provides a framework to imagine how observed complex drug-drug interactions at OCTs arise. Finally, preclinical in vitro tests that are performed by pharmaceutical companies to identify interaction of novel drugs with OCTs are discussed. Optimized experimental procedures are proposed that allow a gapless detection of inhibitory and transported drugs.

Immune Checkpoint Expression on Immune Cells of HNSCC Patients and Modulation by Chemo- and Immunotherapy

Endogenous control mechanisms, including immune checkpoints and immunosuppressive cells, are exploited in the process of tumorigenesis to weaken the anti-tumor immune response. Cancer treatment by chemotherapy or immune checkpoint inhibition can lead to changes of checkpoint expression, which influences therapy success. Peripheral blood lymphocytes (PBL) and tumor-infiltrating lymphocytes (TIL) were isolated from head and neck squamous cell carcinoma (HNSCC) patients (n = 23) and compared to healthy donors (n = 23). Immune checkpoint expression (programmed cell death ligand 1 (PD-1), tumor necrosis factor receptor (TNFR)-related (GITR), CD137, tumor necrosis factor receptor superfamily member 4 (TNFRSF4) (OX40), t-cell immunoglobulin and mucin-domain containing-3 (TIM3), B- and T-lymphocyte attenuator (BTLA), lymphocyte-activation gene 3 (LAG3)) was determined on immune cells by flow cytometry. PD-L1 expression was detected on tumor tissue by immunohistochemistry. Immune cells were treated with immuno- and chemotherapeutics to investigate treatment-specific change in immune checkpoint expression, in vitro. Specific changes of immune checkpoint expression were identified on PBL and TIL of HNSCC patients compared to healthy donors. Various chemotherapeutics acted differently on the expression of immune checkpoints. Changes of checkpoint expression were significantly less pronounced on regulatory T cells compared to other lymphocyte populations. Nivolumab treatment significantly reduced the receptor PD-1 on all analyzed T cell populations, in vitro. The specific immune checkpoint expression patterns in HNSCC patients and the investigated effects of immunomodulatory agents may improve the development and efficacy of targeted immunotherapy.

Overexpression of HURP mRNA in head and neck carcinoma and association with in vitro response to vinorelbine

HURP gene encodes the hepatoma upregulated protein (HURP), a microtubule associated protein regulating mitotic spindle dynamics, which promotes chromosomal congression and alignment during mitosis, with a potential role in tumorigenesis. In the present study, HURP mRNA expression was investigated by reverse transcription-quantitative PCR in oropharyngeal squamous cell carcinoma (OPSCC). Primary OPSCC tumors from 107 patients and 48 adjacent normal tissues, as well as 12 respiratory tract cancer cell lines (9 head and neck squamous cell carcinoma, 2 lung cancer and 1 normal bronchial) were utilised in the present study. mRNA expression levels of HURP were higher in malignant OPSCC tissues compared with in normal mucosa (P<1×10^-5) and significantly associated with sex and smoking status (P<0.0001). Vinorelbine in vitro toxicity at half-maximal inhibitory concentration (IC₅₀) was measured in the 11 cancer cell lines using an MTT assay. Sensitivity to vinorelbine was significantly correlated with HURP expression (r=0.636; P=0.035). The data indicated that HURP overexpression is frequent in OPSCC tissues and associated with smoking. The correlation between HURP mRNA expression and vinorelbine in vitro response suggests that HURP is a potential modulator of vinorelbine response; therefore, it should be explored for its possible predictive value for the efficiency of vinorelbine treatment in this type of cancer.

Synthesis and Cytostatic Effect of 3'-deoxy-3'-C-Sulfanylmethyl Nucleoside Derivatives with d-xylo Configuration

A small library of 3’-deoxy-C3’-substituted xylofuranosyl-pyrimidine nucleoside analogues were prepared by photoinduced thiol-ene addition of various thiols, including normal and branched alkyl-, 2-hydroxyethyl, benzyl-, and sugar thiols, to 3’-exomethylene derivatives of 2’,5’-di-O-tert-butyldimethylsilyl-protected ribothymidine and uridine. The bioactivity of these derivatives was studied on tumorous SCC (mouse squamous carcinoma cell) and immortalized control HaCaT (human keratinocyte) cell lines. Several alkyl-substituted analogues elicited promising cytostatic activity in low micromolar concentrations with a slight selectivity toward tumor cells. Near-infrared live-cell imaging revealed SCC tumor cell-specific mitotic blockade via genotoxicity of analogue 10, bearing an n-butyl side chain. This analogue essentially affects the chromatin structure of SCC tumor cells, inducing a condensed nuclear material and micronuclei as also supported by fluorescent microscopy. The results highlight that thiol-ene chemistry represents an efficient strategy to discover novel nucleoside analogues with non-natural sugar structures as anticancer agents.

Dynamic changes in chemosensitivity immune predictors in patients with hypopharyngeal cancer treated with induction chemotherapy

BACKGROUND

There are currently no data predicting chemosensitivity of induction chemotherapy (ICT) for hypopharyngeal squamous cell carcinomas (SCC).

METHODS

Associations between immune cells and overall response (OR) to ICT and changes in immune cells during ICT were observed in 40 patients with hypopharyngeal SCC undergoing ICT.

RESULTS

CD4⁺ and CD8⁺ T-cell and regulatory T-cell (Treg) frequencies reached diagnostic accuracy for OR to ICT. OR rate was significantly higher in CD4⁺ -high T cell, CD8⁺ -high T cell, and low Treg groups. A transient reduction in Tregs and increases in Tregs in the non-OR and OR groups were observed during the course of ICT. Conversely, increases in CD8⁺ T cells and reductions in CD8⁺ T cells in the non-OR and OR groups were observed.

CONCLUSION

High CD4⁺ T-cell, high CD8⁺ T-cell, and low Treg frequencies can be predictors for high efficacy of ICT in patients with hypopharyngeal SCC.

Systems analysis of phosphorylation-regulated Bcl-2 interactions establishes a model to reconcile the controversy over the significance of Bcl-2 phosphorylation

BACKGROUND AND PURPOSE

The biological significance of the multi-site phosphorylation of Bcl-2 at its loop region (T69, S70 and S87) has remained controversial for decades. This is a major obstacle for understanding apoptosis and anti-tumour drug development.

EXPERIMENTAL APPROACH

We established a mathematical model into which a phosphorylation and de-phosphorylation process of Bcl-2 was integrated. Paclitaxel-treated breast cancer cells were used as experimental models. Changes in the kinetics of binding with its critical partners, induced by phosphorylation of Bcl-2 were experimentally obtained by surface plasmon resonance, using a phosphorylation-mimicking mutant EEE-Bcl-2 (T69E, S70E and S87E).

KEY RESULTS

Mathematical simulations combined with experimental validation showed that phosphorylation regulates Bcl-2 with different dynamics depending on the extent of Bcl-2 phosphorylation and the phosphorylated Bcl-2-induced changes in binding kinetics. In response to Bcl-2 homology 3 (BH3)-only protein Bmf stress, Bcl-2 phosphorylation switched from diminishing to enhancing the Bcl-2 anti-apoptotic ability with increased phosphorylation of Bcl-2, and the turning point was 50% Bcl-2 phosphorylation induced by 0.2 μM paclitaxel treatment. In contrast, Bcl-2 phosphorylation enhanced the anti-apoptotic ability of Bcl-2 towards other BH3-only proteins Bim, Bad and Puma, throughout the entire phosphorylation procedure.

CONCLUSIONS AND IMPLICATIONS

The model could accurately predict the effects of anti-tumour drugs that involve the Bcl-2 family pathway, as shown with ABT-199 or etoposide.

Identification of JNK1 as a predicting biomarker for ABT-199 and paclitaxel combination treatment

Targeting Bcl-2 with ABT-199 (Venetoclax) shows limited single-agent activity against many cancers in both preclinical and clinical investigations. Combination therapies have attracted great attention. The principal purpose of this study was to investigate the mechanism of synergism between ABT-199 and paclitaxel. Moreover, we analyzed the biomarker to identify tumors which are most likely to respond to this combination. We evaluated the effect of this combination in a panel of nine cancer cell lines including cervical cancer, lung cancer, ovarian cancer, lymphoma, leukemia and breast cancer. Combination index (CI) assay showed that four of nine call lines exhibited synergistic respond to ABT-199/paclitaxel combination due to enhanced intrinsic apoptosis. However, paclitaxel-induced Bcl-2 phosphorylation impaired the synergistic effect by impeding the freeing of Bax and Bim by ABT-199 because ABT-199 cannot hit phosphorylated Bcl-2 (pBcl-2). By means of a correlation analysis of JNK level with CI value in combination with overexpressing or silencing JNK protein in cancer cells, we identified basal JNK1 level as a potential biomarker for predicting the level of pBcl-2 upon paclitaxel treatment, and thus for predicting a synergistic response. A cut-off value of 0.37 for relative JNK1 expression level was determined using receiver operating characteristic (ROC) analysis to distinguish between synergistic and non-synergistic response cancers. A more accurate and valid cut-off value for JNK1 will be gained based on a large-scale clinical samples analysis.

The influence of chemotherapy on adenosine-producing B cells in patients with head and neck squamous cell carcinoma

INTRODUCTION

Head and neck squamous cell carcinoma (HNSCC) strongly suppresses the immune system, resulting in increased metastasis and recurrent disease. Chemotherapy is part of the multimodal treatment but may further immunosuppression. Recently, we demonstrated that regulatory B cells (Breg), defined as CD19+CD39+CD73+ B cells, play a significant role in the production of immunosuppressive, extracellular adenosine (ADO). Here, we tested the influence of chemotherapy on Breg function.

RESULTS

In HNSCC patients, Breg were diminished in absolute number and frequency after chemotherapy (paired samples). Chemotherapeutic drugs had variable effects; while platinum-based chemotherapy decreased the expression of CD39, methotrexate led to a functional increase in CD39 expression and increased production of immunosuppressive ADO. These findings were confirmed in a second patient cohort. Surface expression of CD39 correlated strongly with the production of ADO as measured by mass spectrometry.

CONCLUSIONS

Platinum-based anti-tumor-therapy reduces the number of adenosine-producing B cells and, consequently, potential immunosuppression within the tumor environment. Breg function in terms of ADO production and their potential capacity to suppress CD4+ T cells are promoted by methotrexate treatment amplifying anti-inflammatory therapeutic effects. Our results add to the understanding of how chemotherapeutic drugs can influence the human immune system and may therefore help to orchestrate standard oncologic therapy with new immune modulating approaches.

METHODS

Mononuclear cells were collected prospectively from HNSCC patients before and after chemotherapy (n = 18), from healthy donors (n = 20), and an additional cohort sampled several months after chemotherapy (n = 14). Frequency, phenotype, and function of Breg were determined by multicolor flow cytometry, ATP luminescence assay as well as mass spectrometry measuring 5'-AMP, ADO, and inosine. Isolated B cells were incubated with chemotherapeutic drugs (cisplatin, methotrexate, paclitaxel, 5-fluorouracil) in vitro for functional studies.

Immunomodulatory/inflammatory effects of geopropolis produced by Melipona fasciculata Smith in combination with doxorubicin on THP-1 cells

OBJECTIVES

Geopropolis (GEO) in combination with doxorubicin (DOX) reduced HEp-2 cells viability compared to GEO and DOX alone. A possible effect of this combination on the innate immunity could take place, and its effects were analysed on THP-1 cell - a human leukaemia monocytic cell line used as a model to study monocyte activity and macrophage activity, assessing cell viability, expression of cell markers and cytokine production.

METHODS

THP-1 cells were incubated with GEO, DOX and their combination. Cell viability was assessed by MTT assay, cell markers expression by flow cytometry and cytokine production by ELISA.

KEY FINDINGS

GEO + DOX did not affect cell viability. GEO alone or in combination increased TLR-4 and CD80 but not HLA-DR and TLR-2 expression. GEO stimulated TNF-α production while DOX alone or in combination did not affect it. GEO alone or in combination inhibited IL-6 production.

CONCLUSIONS

GEO exerted a pro-inflammatory profile by increasing TLR-4 and CD80 expression and TNF-α production, favouring the activation of the immune/inflammatory response. GEO + DOX did not affect cell viability and presented an immunomodulatory action. Lower concentrations of DOX combined to GEO could be used in cancer patients, avoiding side effects and benefiting from the biological properties of GEO.

Effects of adjuvant chemoradiotherapy on the frequency and function of regulatory T cells in patients with head and neck cancer

PURPOSE

Regulatory T cells (Treg) accumulate in tumor tissues and the peripheral blood of cancer patients and may persist after therapies. This cross-sectional study examines effects of adjuvant chemoradiotherapy (CRT) on Treg numbers and function in head and neck squamous cell carcinoma (HNSCC) patients.

EXPERIMENTAL DESIGN

The frequency and absolute numbers of CD4(+), ATP-hydrolyzing CD4(+)CD39(+) and CD8(+) T cells, and expression levels of CD39, CD25, TGF-β-associated LAP and GARP on Treg were measured by flow cytometry in 40 healthy donors (NC) and 71 HNSCC patients [29 untreated with active disease (AD); 22 treated with surgery; 20 treated with CRT]. All treated subjects had no evident disease (NED) at the time of phlebotomy. In an additional cohort of 40 subjects with AD (n = 15), NED (n = 10), and NC (n = 15), in vitro sensitivity of CD4(+) T-cell subsets to cisplatin and activation-induced cell death (AICD) was tested in Annexin V-binding assays.

RESULTS

CRT decreased the frequency of circulating CD4(+) T cells (P < 0.002) but increased that of CD4(+)CD39(+) Treg (P ≤ 0.001) compared with untreated or surgery-only patients. Treg frequency remained elevated for >3 years. CRT increased surface expression of LAP, GARP, and CD39 on Treg. In vitro Treg were resistant to AICD or cisplatin but conventional CD4(+) T cells (Tconv) were not. CRT-induced Treg from AD or NC subjects upregulated prosurvival proteins whereas Tconv upregulated proapoptotic Bax.

CONCLUSIONS

Highly suppressive, cisplatin-resistant Treg increase in frequency and persist after CRT and could be responsible for suppression of antitumor immune responses and recurrence in HNSCC.

Clinical outcomes of radiation-based locoregional therapy in locally advanced head and neck squamous cell carcinoma patients not responding to induction chemotherapy

OBJECTIVE

The purpose of this study was to evaluate the efficacy of radiation-based locoregional therapy for locally advanced head and neck squamous cell carcinoma (LA-HNSCC) patients who did not respond to induction chemotherapy (IC).

STUDY DESIGN

Outcomes after radiation-based locoregional therapy were retrospectively analyzed.

RESULTS

Among a total of 208 patients treated with IC, 46 (22.1%) did not respond. After IC, patients were treated with radiotherapy (RT), concurrent chemoradiotherapy (CCRT), or surgery with or without postoperative RT. Among the 46 nonresponders, 17 (37.8%) patients underwent surgery and 28 (62.2%) were treated with RT or CCRT. Responses to subsequent RT or CCRT for 26 evaluable patients were as follows: complete response=7 (26.9%), partial response=9 (34.6%), stable disease=4 (15.4%), and progressive disease=6 (23.1%).

CONCLUSION

A significant proportion of LA-HNSCC patients who did not respond to IC can benefit from subsequent RT or CCRT.

Contribution of tumoral and host solute carriers to clinical drug response

Members of the solute carrier family of transporters are responsible for the cellular uptake of a broad range of endogenous compounds and xenobiotics in multiple tissues. Several of these solute carriers are known to be expressed in cancer cells or cancer cell lines, and decreased cellular uptake of drugs potentially contributes to the development of resistance. As result, the expression levels of these proteins in humans have important consequences for an individual's susceptibility to certain drug-induced side effects, interactions, and treatment efficacy. In this review article, we provide an update of this rapidly emerging field, with specific emphasis on the direct contribution of solute carriers to anticancer drug uptake in tumors, the role of these carriers in regulation of anticancer drug disposition, and recent advances in attempts to evaluate these proteins as therapeutic targets.

Do insulin-like growth factor associated proteins qualify as a tumor marker? Results of a prospective study in 163 cancer patients

OBJECTIVE

Insulin-like growth factor (IGF)-1, -2 and Insulin like growth factor binding proteins (IGFBP) are involved in the proliferation and differentiation of cells. It has never been evaluated, if the IGF-system can serve as a tumor marker in neoplasms.

METHODS

In our prospective study 163 patients with colorectal cancer (22), prostate cancer (21), head and neck tumors (17), lymphomas (20), lung cancer (34) and other entities (49) were analysed for their IGF and IGFBP serum levels at the beginning and the end of radiotherapy and compared to 13 healthy people. Subgroups of patients with local tumor disease versus metastatic disease, primary and recurrent therapy and curative versus palliative therapy were compared.

RESULTS

The serum levels of IGF-2 were significantly elevated in patients with prostate and colorectal cancer. However, sensitivity and specificity were only 70%. IGFBP-2 serum levels were elevated in patients with head and neck tumors. Again sensitivity and specificity were only 73%. A difference between local disease and metastatic disease could not be found. A difference between IGF serum levels before and after radiotherapy could not be detected.

CONCLUSION

The IGF-system cannot serve as a new tumor marker. The detected differences are very small, sensitivity and specificity are too low. IGF measurement is not useful for the evaluation of the success of radiotherapy in malignancies.

Trimodal therapy in squamous cell carcinoma of the esophagus

Patients with ESCC (squamous cell carcinoma of the esophagus) are most commonly diagnosed with locally advanced tumor stages. Early metastatic disease and late diagnosis are common reasons responsible for this tumor's poor clinical outcome. The prognosis of esophageal cancer is very poor because patients usually do not have symptoms in early disease stages. Squamous cell carcinoma of the esophagus frequently complicates patients with multiple co-morbidities and these patients often require interdisciplinary diagnosis and treatment procedures. At present time, neoadjuvant radiation therapy and chemotherapy followed by surgery are regarded as the international standard of care. Meta-analyses have confirmed that this approach provides the patient with better local tumor control and an increased overall survival rate. It is recommended that patients with positive tumor response to neoadjuvant therapy and who are poor surgical candidates should consider definitive radiochemotherapy without surgery as a treatment option. In future, EGFR antibodies may also be administered to patients during therapy to improve the current treatment effectiveness. Positron-emission tomography proves to be an early response-imaging tool used to evaluate the effect of the neoadjuvant therapy and could be used as a predictive factor for the survival rate in ESCC. The percentage proportions of residual tumor cells in the histopathological analyses represent a gold standard for evaluating the response rate to radiochemotherapy. In the future, early response evaluation and molecular biological tests could be important diagnostic tools in influencing the treatment decisions of ESCC patients.