Heterogeneity of epithelial and stromal cells of head and neck squamous cell carcinomas in ex vivo chemoresponse

Cytokine Profiles of Head and Neck Squamous Cell Carcinoma Undergoing Dual Immunotherapy With Cetuximab and Pembrolizumab Identify Interferon Gamma-Induced Protein 10 as Novel Biomarker

Background

Pembrolizumab and cetuximab are antibodies under investigation in head and neck squamous cell carcinoma (HNSCC) either as single agents or combined with cisplatin and other chemotherapeutic drugs, e.g., 5-fluorouracil and/or docetaxel. However, also the combination of both antibodies may have potential in recurrent/metastatic (R/M) HNSCC, in particular in cisplatin-resistant or -refractory cases or patients with comorbid disease, e.g. patients with impaired renal function.

Methods

To clarify potential benefit that may result from such combination, we used the FLAVINO assay, a short-time ex vivo assay to compare responsiveness of HNSCC to pembrolizumab, cetuximab and both combined regarding colony formation of epithelial cells of biopsy-derived tumor samples and their cytokine production within three days either without or with stimulation with 10 ng/mL interferon gamma (IFN-γ). Vascular endothelial growth factor A (VEGF), monocyte chemoattractant protein 1 (MCP-1 or CCL2), interleukin 6 (IL-6), IL-8, IFN-γ, and interferon gamma-induced protein 10 (IP-10 or CXCL10) in supernatants were measured by ELISA.

Results

We detected huge heterogeneity in response to cetuximab, pembrolizumab and both combined with and without IFN-γ stimulation. Moreover, we detected a link between IFN-γ induced IP-10 release and improved outcome in those HNSCC patients who were capable to respond to IFN-γ and pembrolizumab, cetuximab and both combined with a further increase in IP-10 production. We derived an “IP-10 score” that independent from clinical characteristics of HNSCC patients and therapy regimens applied was able to predict their outcome.

Conclusions

The heterogeneity in the ex vivo response of cetuximab, pembrolizumab and both combined with and without IFN-γ stimulation identifies subgroups of HNSCC patients with deviating OS.

Homing Peptide-Based Targeting of Tenascin-C and Fibronectin in Endometriosis

The current diagnostic and therapeutic strategies for endometriosis are limited. Although endometriosis is a benign condition, some of its traits, such as increased cell invasion, migration, tissue inflammation, and angiogenesis are similar to cancer. Here we explored the application of homing peptides for precision delivery of diagnostic and therapeutic compounds to endometriotic lesions. First, we audited a panel of peptide phages for the binding to the cultured immortalized endometriotic epithelial 12Z and eutopic stromal HESC cell lines. The bacteriophages displaying PL1 peptide that engages with angiogenic extracellular matrix overexpressed in solid tumors showed the strongest binding to both cell lines. The receptors of PL1 peptide, tenascin C domain C (TNC-C) and fibronectin Extra Domain-B (Fn-EDB), were expressed in both cells. Silver nanoparticles functionalized with synthetic PL1 peptide showed specific internalization in 12Z and HESC cells. Treatment with PL1-nanoparticles loaded with the potent antimitotic drug monomethyl auristatin E decreased the viability of endometriotic cells in 2D and 3D cultures. Finally, PL1-nanoparticless bound to the cryosections of clinical peritoneal endometriotic lesions in the areas positive for TNC-C and Fn-EDB immunoreactivities and not to sections of normal endometrium. Our findings suggest potential applications for PL1-guided nanoparticles in precision diagnosis and therapy of endometriosis.

[Preclinical models to establish innovative therapy strategies : Ex‑vivo assessment of head and neck tumor chemo- and immune responses]

The pharmacological treatment of head and neck squamous cell carcinoma (HNSCC) is currently experiencing an expansion of the spectrum of targeting therapies. It can be expected that use of immune modulators, e.g., checkpoint-inhibitors, and their combination with chemotherapy will lead to a plethora of therapeutic options in the near future, from which the best one for the individual patient can be selected. HNSCCs are heterogeneous in their biology, and responses to chemotherapy are nonuniform and often only observable in subgroups. It would be valuable to know the chance of success of a particular treatment in advance. Evidence-based selection of the best individual treatment is difficult, since predictive biomarkers which are assessable prior to the treatment decision and reliably indicate the suitability of particular therapeutics are lacking. Pretherapeutic predictive ex-vivo chemoresponse testing of HNSCC biopsy specimens could enable identification of responders and allow a more suitable therapy regimen to be chosen for potential non-responders, without exposing them to likely ineffective therapy attempts. However, early ex-vivo assays failed regarding reliable prediction of therapeutic success, even with tolerable doses of pharmaceuticals and, in particular, their combinations. Predictive testing was hence deemed improper for the clinic. Improved methodology has now led to a reappraisal of predictive testing and its additional use in analysis of antitumor immune responses ex vivo. Here we describe recent advances and new results from ex-vivo chemoresponse testing of HNSCC and highlight their ability to facilitate establishment of innovative therapy strategies.

Reduced proliferation and colony formation of head and neck squamous cell carcinoma (HNSCC) after dual targeting of EGFR and hedgehog pathways

PURPOSE

The hedgehog signalling pathway (Hh) is frequently active in head and neck squamous cell carcinoma (HNSCC). Overexpressed Hh associates with poor prognosis. The Hh inhibitor vismodegib targets smoothened, and based on molecular data, may prevent resistance to EGFR targeting.

METHODS

To elucidate potential roles of vismodegib in HNSCC therapy, its sole effects and those combined with cisplatin, docetaxel, and cetuximab on HNSCC cell lines were assessed by MTT metabolisation and BrdU incorporation. Colony formation (CF) of primary HNSCC cells was studied utilizing the FLAVINO-protocol. Combinatory effects were analysed regarding antagonism, additivity or synergism. Associations between the ex vivo detected mode of action of vismodegib with other treatments related to patient characteristics were assessed and progression-free survival (PFS) in patient groups compared using Kaplan-Meier curves.

RESULTS

Vismodegib suppressed BrdU incorporation significantly stronger than MTT turnover; CF was significantly inhibited at ≥20 µM vismodegib while concentrations <20 µM acted hormetic. Combining 20 µM vismodegib plus docetaxel (T), cisplatin (P), and cetuximab (E), additively enhanced anti-tumoral activity in HNSCC samples from patients with superior PFS highlighting a potential role for ex-vivo testing of this combination for use as a prognostic classifier.

CONCLUSION

We provide ex-vivo evidence for vismodegib's potential in HNSCC therapies, especially if combined with cetuximab, cisplatin and docetaxel.

Feasibility of Primary Tumor Culture Models and Preclinical Prediction Assays for Head and Neck Cancer: A Narrative Review

Primary human tumor culture models allow for individualized drug sensitivity testing and are therefore a promising technique to achieve personalized treatment for cancer patients. This would especially be of interest for patients with advanced stage head and neck cancer. They are extensively treated with surgery, usually in combination with high-dose cisplatin chemoradiation. However, adding cisplatin to radiotherapy is associated with an increase in severe acute toxicity, while conferring only a minor overall survival benefit. Hence, there is a strong need for a preclinical model to identify patients that will respond to the intended treatment regimen and to test novel drugs. One of such models is the technique of culturing primary human tumor tissue. This review discusses the feasibility and success rate of existing primary head and neck tumor culturing techniques and their corresponding chemo- and radiosensitivity assays. A comprehensive literature search was performed and success factors for culturing in vitro are debated, together with the actual value of these models as preclinical prediction assay for individual patients. With this review, we aim to fill a gap in the understanding of primary culture models from head and neck tumors, with potential importance for other tumor types as well.

Slice cultures from head and neck squamous cell carcinoma: a novel test system for drug susceptibility and mechanisms of resistance

Background:

Human head and neck squamous cell carcinoma (HNSCC) fundamentally vary in their susceptibility to different cytotoxic drugs and treatment modalities. There is at present no clinically accepted test system to predict the most effective therapy for an individual patient.

Methods:

Therefore, we established tumour-derived slice cultures which can be kept in vitro for at least 6 days. Upon treatment with cisplatin, docetaxel and cetuximab, slices were fixed and paraffin sections were cut for histopathological analysis.

Results:

Apoptotic fragmentation, activation of caspase 3, and cell loss were observed in treated tumour slices. Counts of nuclei per field in untreated compared with treated slices deriving from the same tumour allowed estimation of the anti-neoplastic activity of individual drugs on an individual tumour.

Conclusion:

HNSCC-derived slice cultures survive well in vitro and may serve not only to improve personalised therapies but also to detect mechanisms of tumour resistance by harvesting surviving tumour cells after treatment.

Optical molecular imaging approach for rapid assessment of response of individual cancer cells to chemotherapy

Predicting the response of individual patients to cytotoxic chemotherapy drugs is critical for developing individualized therapies. With this motivation, an optical molecular imaging approach was developed to detect cisplatin induced changes in the uptake and intracellular retention of choline. Intracellular uptake of choline was characterized using a click chemistry reaction between propargyl choline and Alexa-488 azide. Cisplatin induced changes in the uptake of propargyl choline in cells and tumor spheroids were compared with similar measurements using a fluorescent analogue of deoxyglucose and conventional cell viability assays. Uptake and intracellular retention of propargyl choline decreased with an increase in concentration of cisplatin. Intracellular uptake of propargyl choline was significantly reduced within 3 h of incubation with a sub-lethal dose of cisplatin. Results demonstrate that the imaging approach based on propargyl choline was more sensitive in detecting the early response of cancer cells to cisplatin as compared to the imaging based on fluorescent analogue of deoxyglucose and cell viability assays. Imaging measurements in tumor spheroids show a significant decrease in the uptake of propargyl choline following treatment with cisplatin. Overall, the results demonstrate a novel optical molecular imaging approach for rapid measurement of the response of individual cancer cells to cisplatin treatment.

[Pharmacological characterization of head and neck cancer in ex-vivo tests]

Precise knowledge about the chance of success of a given pharmacologic therapy of head and neck squamous cell carcinoma (HNSCC) before starting therapy would be very desirable to guide the selection of the most suitable or the most efficient combination out of the ever-growing spectrum of available pharmaceuticals. This selection has hitherto been made at best on the basis of the availability of guideline-conformant and approved combinations according to results of published clinical studies and approved general effectiveness in HNSCC. However, the inhomogeneous biology of HNSCC depending on localization, varying metastatic behavior, TNM and UICC stage in the context of the patient's general condition and risk status according to lifestyle and occupational exposure make it impossible to accurately predict the success of pharmacological therapy regimens for the individual HNSCC based on today's clinical and pathohistological diagnostics. A solution may lie in the testing of biopsy specimens ex vivo before starting therapy. The present review describes recent advances in ex-vivo tests and discusses the requirements for their inclusion in the decision-making process.

[Current therapy options in recurrent head and neck cancer]

Recurrent disease is one of the main reasons for the persistently poor prognosis of squamous cell carcinoma of the head and neck (HNSCC; European 5-year survival, 42%). The main treatment option for primary and secondary malignancy as well as recurrent disease is surgical therapy. If R0 resection (resection margin >5 mm) for a primary tumor is not viable, survival probability is reduced by 50%. In recurrent or secondary tumors with R1- or -2 resection or in the presence of non-resectable metastases, a palliative situation results in more than 80% of cases. In the case of surgery following radiotherapy or radiochemotherapy, attention should be paid to the criteria for salvage surgery (tissue perfusion, fibrosis, wound healing) and the procedure adapted to focus on functionality. In the case of relapse, primary surgery can potentially be supplemented with adjuvant therapy protocols such as (re-) irradiation, as well as possibly with chemotherapeutic agents or targeted therapies. Interdisciplinary collaboration and case discussions should take place in the context of a tumor board.

Assay-based response evaluation in head and neck oncology: requirements for better decision making

This article gives an overview on different current strategies of assay-based response evaluation in head and neck squamous cell carcinomas (HNSCC) and critically summarizes their role and needs for future clinical evaluation. Due to a growing amount of data of phase III clinical trials of multimodality treatment options for HNSCC, treatment planning in regard to optimal outcome is becoming an interdisciplinary challenge. New concepts such as induction chemotherapy with bi- or ternary combinations of chemotherapeutics, integration of targeted therapies, concurrent and sequential chemoradiation concepts, and multimodality-based organ preservation strategies strongly compete with traditional definitive surgical procedures. Moreover, the outcome is difficult to predict due to heterogeneity of a tumor's response, impaired late functional outcome, and increased late toxicity if simultaneously applied to radiation. Retrospectively looking at non-responders with tumors classified as resectable, primary surgery is very likely to have achieved better results, since chemoradiation causes a high degree of early and late toxicities leading to extremely complicated terms and conditions in surgery following current multimodal therapeutic strategies. Unfortunately, predictive information on response characteristics of a given tumor before starting the therapy is not available in daily routine, although heterogeneity in response of a given tumor entity to treatments has been known for decades. Therefore, current therapy strategies for HNSCC still have to ignore this fact, creating an urgent need for the development of proper predictive assays. There are interesting clinical observations showing that response on induction chemotherapy may predict the outcome after radiotherapy. Some trials use this empiric phenomenon to pre-select non-responders for primary surgical treatment avoiding severe salvage complications after failure of complete chemoradiation treatment. Moving one step further, recent literature and our own investigations implicate that response evaluation of the individual patient's HNSCC in a suitable ex vivo assay just before starting the treatment is mature for clinical research. To this end, essential needs and hints are addressed and discussed.