The epidermal growth factor receptor in squamous cell carcinoma: An emerging drug target

EGFR and HER-2 oncogenes expression in an experimental model of two-stage chemically induced carcinogenesis in mouse skin

The aim of the study was to investigate the expression of EGFR and HER-2 oncogenes using an experimental two stage chemically induced carcinogenesis protocol on the dorsal skin in FVB/N mice. Forty female FVB/N mice 4 weeks old, were grouped into one control (n = 8) and two experimental groups (Group A: n = 16, Group B: n = 16) following a randomization process. Two-stage carcinogenesis protocol, was implicated, including an initial treatment with 97.4 nmol DMBA on their shaved dorsal skin and subsequent treatments of 32.4 nmol TPA applications after 13 weeks for Group A and after 20 weeks for Group B. The control group C, received no treatment. Skin was examined weekly for tumor development. Post-experiment, animals were euthanized for tissue analysis. The histological status of the skin lesions in the experimental groups corresponded well with tumour advancement (from dysplasia to poorly-differentiated carcinoma). Tumour sections were evaluated histologically and immunohistochemically. EGFR expression was found significantly higher in precancerous and malignant tumours (p = 042 and p = 008 respectively), while tended to be higher in benign tumours (p = 079), compared to normal histology. Moreover, mean percentage of EGFR positive expression in malignant tumours was significantly higher than in benign tumours (p < 001). HER-2 expression was found significantly higher in precancerous and malignant tumours (p = 042 and p = 015 respectively), while tended to be higher in benign tumours (p = 085), compared to normal histology. Furthermore, mean percentage of HER-2 positive expression in malignant tumours was significantly higher than in benign tumours (p = 005). The study demonstrated that in FVB/N mice subjected to a two-stage chemically induced carcinogenesis protocol, there was a significant increase in the expression of EGFR and HER-2 oncogenes in precancerous and malignant skin lesions compared to normal tissue. This suggests a potentially early role of these oncogenes in the progression of skin tumours in this model.

Anti-Gene IGF-I Vaccines in Cancer Gene Therapy: A Review of a Case of Glioblastoma

OBJECTIVE

Vaccines for the deadliest brain tumor - glioblastoma (GBM) - are generally based on targeting growth factors or their receptors, often using antibodies. The vaccines described in the review were prepared to suppress the principal cancer growth factor - IGF-I, using anti-gene approaches either of antisense (AS) or of triple helix (TH) type. Our objective was to increase the median survival of patients treated with AS and TH cell vaccines.

METHODOLOGY

The cells were transfected in vitro by both constructed IGF-I AS and IGF-I TH expression episomal vectors; part of these cells was co-cultured with plant phytochemicals, modulating IGF-I expression. Both AS and TH approaches completely suppressed IGF-I expression and induced MHC-1 / B7 immunogenicity related to the IGF-I receptor signal.

RESULTS

This immunogenicity proved to be stronger in IGF-I TH than in IGF-I AS-prepared cell vaccines, especially in TH / phytochemical cells. The AS and TH vaccines generated an important TCD8+ and TCD8+CD11b- immune response in treated GBM patients and increased the median survival of patients up to 17-18 months, particularly using TH vaccines; in some cases, 2- and 3-year survival was reported. These clinical results were compared with those obtained in therapies targeting other growth factors.

CONCLUSION

The anti-gene IGF-I vaccines continue to be applied in current GBM personalized medicine. Technical improvements in the preparation of AS and TH vaccines to increase MHC-1 and B7 immunogenicity have, in parallel, allowed to increase in the median survival of patients.

EGFR and αvβ6 as Promising Targets for Molecular Imaging of Cutaneous and Mucosal Squamous Cell Carcinoma of the Head and Neck Region

R0 resection is paramount in cutaneous squamous cell carcinoma (CSCC) and head and neck squamous cell carcinoma (HNSCC). However, in the setting of recurrence, immunocompromised patients, or non-keratinizing squamous cell carcinoma (SCC) with a spindle growth pattern, tumor borders are difficult, if not impossible, to determine. Fluorescence-guided surgery (FGS) aids in this differentiation. Potential targets for FGS of CSCC and HNSCC were evaluated. Most sections stained intensely for αvβ6 and epidermal growth factor receptor (EGFR) on tumor cells. Normal epithelium stained less for αvβ6 than for EGFR. In addition, soft tissue and stroma stained negative for both, allowing for clear discrimination of the soft tissue margin. Tumor cells weakly expressed urokinase plasminogen activator receptor (uPAR) while expression on stromal cells was moderate. Normal epithelium rarely expressed uPAR, resulting in clear discrimination of superficial margins. Tumors did not consistently express integrin β3, carcinoembryonic antigen, epithelial cell adhesion molecule, or vascular endothelial growth factor A. In conclusion, αvβ6 and EGFR allowed for precise discrimination of SSC at the surgically problematic soft tissue margins. Superficial margins are ideally distinguished with uPAR. In the future, FGS in the surgically challenging setting of cutaneous and mucosal SCC could benefit from a tailor-made approach, with EGFR and αvβ6 as targets.

Epidermal Growth Factor Receptor's Function in Cutaneous Squamous Cell Carcinoma and Its Role as a Therapeutic Target in the Age of Immunotherapies

OPINION STATEMENT

Recent studies have evidenced the potential of combining anti-EGFR therapies with anti-PD-1/PD-L1 checkpoint therapies. Both anti-EGFR and anti-PD-1/PD-L1 have been separately tested in the treatment of cutaneous SCC (cSCC). Here, we review recent data on EGFR in the context of cancer progression, as a prognostic and as a therapeutic target in cSCC. Anti-EGFR/checkpoint immunotherapy and other combination therapy approaches are discussed. With the advent of immunotherapy, EGFR is still a valid cSCC target.

Squamous Cell Carcinoma with Regional Metastasis to Axilla or Groin Lymph Nodes: a Multicenter Outcome Analysis

BACKGROUND

Cutaneous squamous cell carcinoma (cSCC) of the trunk/extremities with nodal metastasis represents a rare but significant clinical challenge. Treatment patterns and outcomes are poorly described.

PATIENTS AND METHODS

Patients with cSCC who developed axilla/groin lymph node metastasis and underwent curative-intent surgery between 2005 and 2015 were identified at four Canadian academic centers. Demographics, tumor characteristics, treatment patterns, recurrence rates, and mortality were described. Overall survival (OS) and disease-free survival (DFS) were calculated using Kaplan-Meier analysis. Predictors of survival and any recurrence were explored using Cox regression and logistic regression models, respectively.

RESULTS

Of 43 patients, 70% were male (median age 74 years). Median follow-up was 38 months. Median time to nodal metastasis was 11.3 months. Thirty-one and 12 patients had nodal metastasis to the axilla and groin, respectively. A total of 72% and 7% received adjuvant and neoadjuvant radiation, respectively, while 5% received adjuvant chemotherapy. Following surgery, 26% patients developed nodal and/or distant disease recurrence. Crude mortality rate was 39.5%. Mean OS was 5.3 years [95% confidence interval (CI) 3.9-6.8 years], and 5-year OS was 55.1%. Mean DFS was 4.8 years (95% CI 3.3-6.2 years), and five-year DFS was 49.3%. Any recurrence was the only independent predictor of death [p = 0.036, odds ratio (OR) = 29.5], and extracapsular extension (p = 0.028, OR = 189) and age (p = 0.017, OR = 0.823) were independent predictors of recurrence.

CONCLUSIONS

This represents the largest contemporary series to date of outcomes for patients with axilla/groin nodal metastases from cSCC. Despite aggressive treatment, outcomes remain modest, indicating the need for a continued multidisciplinary approach and integration of new systemic agents.

Mammalian meat allergy

Mammalian meat allergy is an allergic reaction mediated by IgE antibodies directed against the mammalian oligosaccharide epitope galactose-α-1,3-galactose. Clinically, it is characterized by a range of symptoms including urticaria, angioedema, gastroenteritis, and anaphylaxis hours following ingestion of red meat. It is an emergent allergy in tick endemic areas across the world. As a recently described disease with a cutaneous presentation, dermatologists should be familiar with this entity and recognize it as a differential diagnosis for urticarial and anaphylaxis reactions.

HPV Could be a Potential Factor of Survival in Laryngeal Cancer: a Preliminary Study in Mexican Patients

Introduction: In Head and Neck (HN) cancer, the High-Risk Human Papillomavirus (hr HPV) infection has been associated in about 40% of these tumors. The hr HPV infection is one of the etiological factors of several epithelial tumors; however, its association with the prognosis has not yet been established for patients with Laryngeal Squamous Cell Carcinoma (LSCC). On the other hand, Epidermal Growth Factor Receptor (EGFR) is a molecular marker widely studied in cancer and its overexpression has been associated with poor prognosis in some types of cancer, including the HN cancer. In the present study, we analyzed EGFR expression and HPV detection in a cohort of Mexican patients with LSCC and define their association with clinical-pathological and survival parameters. Methods: EGFR expression analysis was performed by immunohistochemistry assay. A tissue array was constructed based on 30 paraffin-embedded tissue samples. HPV detection was performed by PCR. The results were then compared with the clinical-pathological variables and outcome measures (Kaplan Meier and Cox analysis). Results: High expression of EGFR was observed in 43% of the samples and 20% of HPV detection. The statistical analyses provided evidence of disassociation between clinical-pathological parameters and EGFR expression, but there was an association with poor prognosis. Interestingly, HPV detection is slightly associated with good prognosis. Conclusion: Both, EGFR overexpression and HPV presence could be associated with an unfavorable prognosis in patients with LSCC, independently of other clinical-pathological factors.

Construction of a plasmid vector containing epidermal growth factor receptor and C-Jun shRNA

The objective of this study was to construct a plasmid vector for EGFR-hm-1 and C-Junh-825 small interfering RNA (siRNA). EGFR-hm-1 and C-Jun-hm-825 oligonucleotide fragments were synthesized and short hairpin RNA (shRNA) were amplified by PCR. Plasmids were isolated from E. coli TOP10 bacterium by restriction enzyme digestion using pst1 and BamH1 and oligonucleotide fragments were cloned into the pSilencer plasmid containing the U6 promoter. Recombinant clones were generated by transforming JM109 competent cells with plasmid vectors containing shRNA molecules. 58 base-paired EGFR-hm-1 and 59 base-paired C-Jun-hm-825 oligonucleotide fragments were isolated. The fragments were 100% homologous with human sequences available on GenBank. The recombinant pSilencer1.0 vector containing a 58-bp EGFR-hm-1 and 59-bp C-Jun-hm-825 fragment was constructed. These vectors have the potential to be used as treatment to combat skin photoaging under UV exposure.

Management of High-Risk Squamous Cell Carcinoma of the Skin

OPINION STATEMENT

Non-melanoma skin cancer (NMSC) is the most common malignancy in the USA, with cutaneous squamous cell carcinomas (cSCCs) constituting approximately 20 % of all NMSC. While cSCCs typically behave in an indolent fashion and can be cured with local destructive or surgical methods, a small subset metastasizes and induces significant morbidity and mortality. Identifying and aggressively treating these "high-risk" cSCCs (HRcSCCs) is thus paramount. Recent improvements in staging cSCCs appear to offer better risk stratification than earlier staging criteria. Radiologic imaging and sentinel lymph node biopsy may be beneficial in certain cases of HRcSCC, although more studies are needed before these techniques should be uniformly incorporated into management. Surgery with complete margin control, such as that offered by the Mohs micrographic technique, represents the first-line treatment for these tumors. Radiation therapy is likely most beneficial in the adjuvant setting. Chemotherapy is typically best reserved for patients with metastatic or locally advance disease that is not controllable with surgical and/or radiation therapies. Newer targeted treatments, such as EGFR inhibitors and immunotherapies may offer greater efficacy in these settings, although further evaluation is needed.

Malignant skin tumors: Kids are not just little people

Skin tumors are a clinically heterogeneous group of dermatologic conditions that affect both children and adults. Although similar types of skin tumors can affect both children and adults, the epidemiology, pathogenesis, and treatment of these skin neoplasms can vary drastically in children compared with adults. Despite the clear need for literature elucidating the differences of skin tumors in children compared with adults, there is a serious dearth of scientific contributions addressing this area. This contribution highlights the types of differences that can occur between adults and children with skin neoplasms, as well as the special considerations that need to be recognized when managing skin tumors in children by providing a comparative analysis of basal cell carcinoma, squamous cell carcinoma, and Kaposi sarcoma occurring in adults with these same tumors occurring in children. Specifically, we examine the aforementioned tumors with a focus on (1) epidemiology, (2) etiology, (3) clinical presentation, (4) workup, and (5) treatment.

Molecular signaling cascades involved in nonmelanoma skin carcinogenesis

Nonmelanoma skin cancer (NMSC) is the most common cancer worldwide and the incidence continues to rise, in part due to increasing numbers in high-risk groups such as organ transplant recipients and those taking photosensitizing medications. The most significant risk factor for NMSC is ultraviolet radiation (UVR) from sunlight, specifically UVB, which is the leading cause of DNA damage, photoaging, and malignant transformation in the skin. Activation of apoptosis following UVR exposure allows the elimination of irreversibly damaged cells that may harbor oncogenic mutations. However, UVR also activates signaling cascades that promote the survival of these potentially cancerous cells, resulting in tumor initiation. Thus, the UVR-induced stress response in the skin is multifaceted and requires coordinated activation of numerous pathways controlling DNA damage repair, inflammation, and kinase-mediated signal transduction that lead to either cell survival or cell death. This review focuses on the central signaling mechanisms that respond to UVR and the subsequent cellular changes. Given the prevalence of NMSC and the resulting health care burden, many of these pathways provide promising targets for continued study aimed at both chemoprevention and chemotherapy.

Oncodomains: A protein domain-centric framework for analyzing rare variants in tumor samples

The fight against cancer is hindered by its highly heterogeneous nature. Genome-wide sequencing studies have shown that individual malignancies contain many mutations that range from those commonly found in tumor genomes to rare somatic variants present only in a small fraction of lesions. Such rare somatic variants dominate the landscape of genomic mutations in cancer, yet efforts to correlate somatic mutations found in one or few individuals with functional roles have been largely unsuccessful. Traditional methods for identifying somatic variants that drive cancer are 'gene-centric' in that they consider only somatic variants within a particular gene and make no comparison to other similar genes in the same family that may play a similar role in cancer. In this work, we present oncodomain hotspots, a new 'domain-centric' method for identifying clusters of somatic mutations across entire gene families using protein domain models. Our analysis confirms that our approach creates a framework for leveraging structural and functional information encapsulated by protein domains into the analysis of somatic variants in cancer, enabling the assessment of even rare somatic variants by comparison to similar genes. Our results reveal a vast landscape of somatic variants that act at the level of domain families altering pathways known to be involved with cancer such as protein phosphorylation, signaling, gene regulation, and cell metabolism. Due to oncodomain hotspots' unique ability to assess rare variants, we expect our method to become an important tool for the analysis of sequenced tumor genomes, complementing existing methods.

Mitochondrially Targeted Nanoparticles Based on α-TOS for the Selective Cancer Treatment

The aim of this work is the preparation of an active nanovehicle for the effective administration of α-tocopheryl succinate (α-TOS). α-TOS is loaded in the core of nanoparticles (NPs) based on amphiphilic pseudo-block copolymers of N-vinyl pyrrolidone and a methacrylic derivative of α-TOS. These well-defined spherical NPs have sizes below 165 nm and high encapsulation efficiencies. In vitro activity of NPs is tested in hypopharynx squamous carcinoma (FaDu) cells and nonmalignant epithelial cells, demonstrating that the presence of additional α-TOS significantly enhances its antiproliferative activity; however, a range of selective concentrations is observed. These NPs induce apoptosis of FaDu cells by activating the mitochondria death pathway (via caspase-9). Both loaded and unloaded NPs act via complex II and produce high levels of reactive oxygen species that trigger apoptosis. Additionally, these NPs effectively suppress the vascular endothelial growth factor (VEGF) expression of human umbilical vein endothelial cells (HUVECs). These results open the possibility to use this promising nanoformulation as an α-TOS delivery system for the effective cancer treatment, effectively resolving the current limitations of free α-TOS administration.

Squamous cell carcinoma in a psoriasis patient after multiple courses of phototherapy

The authors present a clinical case study of squamous cell carcinoma in a psoriasis patient after 24 courses of phototherapy (22 courses of PUVA therapy and two courses of mid-wavelength ultraviolet therapy (311 nm)). The malignant neoplasm developed against the background of signs of a chronic photodamage of the skin: lentigo, actinic elastosis, diffuse hyperpigmentation, spotty skin pigmentation.

Possible association between actinic keratosis and the rs7208422 (c.917A→T, p.N306l) polymorphism of the EVER2 gene in patients without epidermodysplasia verruciformis

BACKGROUND

Mutations of the EVER1 and EVER2 genes cause epidermodysplasia verruciformis (EV), a genodermatosis associated with squamous cell carcinoma (SCC). Recently, it has been found that the rs7208422 (c.917A→T, p.N306l) polymorphism in the EVER2 gene is related to an increased risk of SCC in patients with conditions other than EV. We hypothesized that this polymorphism might be also associated with actinic keratoses (AK).

AIM

To determine whether the rs7208422 polymorphism of the EVER2 gene is associated with AK in non-EV patients.

METHODS

We genotyped rs7208422 in 65 patients with AK and 274 controls, using reverse transcription PCR.

RESULTS

We detected a trend towards an association between AK and the TT genotype of rs7208422; the frequency of this genotype was 38.5% in patients with AK and 26.3% in controls (OR  =  1.75, P  <  0.06 for recessive model of inheritance). We also found an association between rs7208422 TT and both the age at which AK appeared and the extent of the AK. This variant was more frequent in patients who had AK onset before the age of 70 years compared with those whose age of onset was above 70 years (OR = 3.14, P = 0.03 for the recessive model; OR = 2.05, P = 0.04 for allelic comparison) and more frequent in AK involving > 3 body areas (OR = 3.14, P = 0.03 for the recessive model; OR = 2.34, P = 0.01 for allelic comparison). These associations remained significant in a multivariate regression analysis, showing that both parameters were independently associated with the TT genotype (P = 0.031).

CONCLUSIONS

This study indicates a potential role of the rs7208422 (c.917A→T, P.N306l) polymorphism of the EVER2 gene in AK.

Advances in the management of cutaneous squamous cell carcinoma

Cutaneous squamous cell carcinoma is one of the most common non-melanoma skin cancers worldwide. While most cutaneous squamous cell carcinomas are easily managed, there is a high-risk subset of tumors that can cause severe morbidity and mortality. Tumor characteristics as well as patient characteristics contribute to the classification of cutaneous squamous cell carcinomas as low-risk vs. high-risk. Advances in the treatment of cutaneous squamous cell carcinomas largely relate to the management of this high-risk subset. Surgical and non-surgical management options, including newer targeted molecular therapies, will be discussed here. Larger, multicenter studies are needed to determine the exact significance of individual risk factors with respect to aggressive clinical behavior and the risks of metastasis and death, as well as the role of surgical and adjuvant therapies in patients with high-risk cutaneous squamous cell carcinomas.