Aggressive cutaneous squamous cell carcinoma (cSCC) is often a disfiguring and lethal disease. Very little is currently known about the mutations that drive aggressive cSCC.
Whole-exome sequencing ...was performed on 39 cases of aggressive cSCC to identify driver genes and novel therapeutic targets. Significantly, mutated genes were identified with MutSig or complementary methods developed to specifically identify candidate tumor suppressors based upon their inactivating mutation bias.
Despite the very high-mutational background caused by UV exposure, 23 candidate drivers were identified, including the well-known cancer-associated genes TP53, CDKN2A, NOTCH1, AJUBA, HRAS, CASP8, FAT1, and KMT2C (MLL3). Three novel candidate tumor suppressors with putative links to cancer or differentiation, NOTCH2, PARD3, and RASA1, were also identified as possible drivers in cSCC. KMT2C mutations were associated with poor outcome and increased bone invasion.
The mutational spectrum of cSCC is similar to that of head and neck squamous cell carcinoma and dominated by tumor-suppressor genes. These results improve the foundation for understanding this disease and should aid in identifying and treating aggressive cSCC.
The solid tumour microenvironment includes nerve fibres that arise from the peripheral nervous system
. Recent work indicates that newly formed adrenergic nerve fibres promote tumour growth, but the ...origin of these nerves and the mechanism of their inception are unknown
. Here, by comparing the transcriptomes of cancer-associated trigeminal sensory neurons with those of endogenous neurons in mouse models of oral cancer, we identified an adrenergic differentiation signature. We show that loss of TP53 leads to adrenergic transdifferentiation of tumour-associated sensory nerves through loss of the microRNA miR-34a. Tumour growth was inhibited by sensory denervation or pharmacological blockade of adrenergic receptors, but not by chemical sympathectomy of pre-existing adrenergic nerves. A retrospective analysis of samples from oral cancer revealed that p53 status was associated with nerve density, which was in turn associated with poor clinical outcomes. This crosstalk between cancer cells and neurons represents mechanism by which tumour-associated neurons are reprogrammed towards an adrenergic phenotype that can stimulate tumour progression, and is a potential target for anticancer therapy.
Penile Squamous Cell Carcinoma (PSCC) is associated with high-risk human papillomavirus (HR-HPV). The immunohistochemical (IHC) test for p16
(p16) is highly correlated with HR-HPV expression in other ...SCCs. To investigate whether the expression of p16 IHC or HR-HPV is associated with survival in PSCC, we conducted a single institution analysis of 143 patients with a diagnosis of PSCC and, available tissue were tested for p16 IHC staining patterns, histological subtype, tumor grade, and lymphovascular invasion (LVI) by an experienced pathologist. HR-HPV status using the Cobas PCR Assay or the RNAScope high-risk HPV in situ hybridization kit were also assessed. Patient characteristics were summarized using descriptive statistics of clinico-pathologic variables. Kaplan-Meier was used to estimate median overall survival (OS), cancer specific survival (CSS) and correlated with HPV, p16, and other study variables. Patients with p16+ tumors had a significantly longer median CSS in comparison to the p16- group (
= 0.004), with respective 5-year CSS probability of 88% (95% CI; 0.84, 1) versus 58% (95% CI; 0.55, 0.76;
= 0.004). HPV status did not predict survival outcomes. Multivariable analysis with respect to OS and CSS, showed that p16+ status was associated with a lower risk of death (HR = 0.36, 95%CI; 0.20-0.67,
= 0.001), and improved CSS (HR = 0.20, 95% CI; 0.07-0.54,
= 0.002) after adjusting for covariates. In conclusion, tumor p16 status via IHC was an easy to perform independent prognostic factor for OS and CSS that correlates with HR-HPV expression.
PURPOSE OF REVIEWWe summarize the recent developments in the molecular landscape of penile squamous cell carcinoma (PSCC).
RECENT FINDINGSRecent genomic studies have demonstrated a molecular ...convergence of PSCC with other squamous cell carcinomas (SCCs) from different organ sites. Similarly, human papillomavirus (HPV)-related PSCCs appear to have epigenetic and genomic similarities with other HPV-related cancers. This could have implications on future HPV-related cancer trial design. Growing efforts to characterize recurrent gene alterations in PSCC have expanded our understanding over the past years, showing a predominance of tumor suppressor gene alterations such as TP53 and NOTCH1. In addition, these studies have demonstrated that at least 30% of PSCC cases have targetable gene alterations. Further, the similar tumor mutational burden with other SCCs and the relatively high rates of programmed death-1 (PD-1) positive expression in PSCC constitute the rationale for investigation of PD-1 inhibition in ongoing clinical trials. Multiple studies have identified potential epigenetic and RNA signatures predictive of metastasis or survival, but these still require validation in larger cohorts.
SUMMARYPSCC appears to be genomicaly similar to other SCCs and HPV-related cancers. This provides the rationale and opportunity to include a rare tumor like PSCC in future ‘basket type’ trials using novel agents targeting multiple SCCs that may exhibit similar biology.
Human cell lines are useful for studying cancer biology and preclinically modeling cancer therapy, but can be misidentified and cross-contamination is unfortunately common. The purpose of this study ...was to develop a panel of validated head and neck cell lines representing the spectrum of tissue sites and histologies that could be used for studying the molecular, genetic, and phenotypic diversity of head and neck cancer.
A panel of 122 clinically and phenotypically diverse head and neck cell lines from head and neck squamous cell carcinoma, thyroid cancer, cutaneous squamous cell carcinoma, adenoid cystic carcinoma, oral leukoplakia, immortalized primary keratinocytes, and normal epithelium was assembled from the collections of several individuals and institutions. Authenticity was verified by carrying out short tandem repeat analysis. Human papillomavirus (HPV) status and cell morphology were also determined.
Eighty-five of the 122 cell lines had unique genetic profiles. HPV-16 DNA was detected in 2 cell lines. These 85 cell lines included cell lines from the major head and neck primary tumor sites, and close examination shows a wide range of in vitro phenotypes.
This panel of 85 genomically validated head and neck cell lines represents a valuable resource for the head and neck cancer research community that can help advance understanding of the disease by providing a standard reference for cell lines that can be used for biological as well as preclinical studies.
The survival of patients with oral squamous cell carcinoma (OSCC) has not changed significantly in several decades, leading clinicians and investigators to search for promising molecular targets. To ...this end, we conducted comprehensive genomic analysis of gene expression, copy number, methylation, and point mutations in OSCC. Integrated analysis revealed more somatic events than previously reported, identifying four major driver pathways (mitogenic signaling, Notch, cell cycle, and TP53) and two additional key genes (FAT1, CASP8). The Notch pathway was defective in 66% of patients, and in follow-up studies of mechanism, functional NOTCH1 signaling inhibited proliferation of OSCC cell lines. Frequent mutation of caspase-8 (CASP8) defines a new molecular subtype of OSCC with few copy number changes. Although genomic alterations are dominated by loss of tumor suppressor genes, 80% of patients harbored at least one genomic alteration in a targetable gene, suggesting that novel approaches to treatment may be possible for this debilitating subset of head and neck cancers.
Therapeutic innovation for human papilloma virus‐related (HPV+) head and neck squamous cell carcinomas (HNSCCs) is impaired by inadequate preclinical models and the absence of accurate biomarkers. ...Our study establishes the first well‐characterized panel of patient‐derived xenografts (PDXs) and organoids from HPV+ HNSCCs while determining fidelity of the models to the distinguishing genetic features of this cancer type. Despite low engraftment rates, whole exome sequencing showed that PDXs retain multiple distinguishing features of HPV+ HNSCC lost in existing cell lines, including PIK3CA mutations, TRAF3 deletion and the absence of EGFR amplifications. Engrafted HPV+ tumors frequently contained NOTCH1 mutations, thus providing new models for a negatively prognostic alteration in this disease. Genotype‐phenotype associations in the models were then tested for prediction of tumor progression and survival in published clinical cohorts. Observation of high tumor mutational burdens (TMBs) in the faster‐growing models facilitated identification of a novel association between TMB and local progression in both HPV+ and HPV− patients that was prognostic in HPV− cases. In addition, reduced E7 and p16INK4A levels found in a PDX from an outlier case with lethal outcome led to detection of similar profiles among recurrent HPV+ HNSCCs. Transcriptional data from the Cancer Genome Atlas was used to demonstrate that the lower E2F target gene expression predicted by reduced E7 levels has potential as a biomarker of disease recurrence risk. Our findings bridge a critical gap in preclinical models for HPV+ HNSCCs and simultaneously reveal novel potential applications of quantifying mutational burden and viral oncogene functions for biomarker development.
What's new?
While the incidence of human papillomavirus (HPV)‐related head and neck squamous cell carcinoma (HNSCC) is increasing, therapeutic development has been slow to progress, due in part to insufficient biomarkers and lack of experimental models. Here, the authors present detailed characterization of HPV‐positive patient‐derived xenograft (PDX) and organoid models generated from HPV‐positive HNSCCs, which typically grow poorly outside the human body. The models retained genetic hallmarks frequently lost in HPV‐positive HNSCC cell lines. In addition, fast growing PDX and organoid models were found to harbor a high tumor mutational burden, which predicted tumor progression and survival when tested in patient cohorts.
Penile squamous cell carcinoma (PSCC) is rare with limited treatment options. We report the first whole-exome sequencing (WES) analysis and compare the molecular landscape of PSCC with other squamous ...cell carcinomas (SCC), with the goal to identify common novel targets.
PSCC and matched normal penile tissues from 34 prospectively followed patients, underwent genomic WES and human papilloma virus testing. We performed tumor mutation signature estimation by two methods, first to identify APOBEC-related mutation enrichments and second to classify PSCC-enriched mutational patterns based on their association with the Catalogue of Somatic Mutations in Cancer mutation signatures. We performed an extensive genomic comparison between our PSCC cohort and other SCCs in The Cancer Genome Atlas studies.
We identified that most PSCC samples showed enrichment for Notch pathway (
= 24, 70.6%) alterations, comparable with head and neck squamous cell carcinoma (HNSC). PSCC mutation signatures are most comparable with HNSC signatures. PSCC samples showed an enrichment of two distinct mutational signatures, the first, associated with oncogenic activity of AID/APOBEC, and the second, associated with defective DNA mismatch repair and microsatellite instability. MP1 enrichment was positively correlated with increased tumor mutation burden (TMB; CC, 0.71;
< 0.0001) and correlated with significantly worse survival in comparison with those with the MP2 subset HR, 10.2 (1.13-92.9);
= 0.039. We show that a subset of PSCC (38%), with enrichment of APOBEC-related mutation signature, had significantly higher TMB and worse overall survival in comparison with non-APOBEC-enriched subset HR, 2.41 (1.11-6.77);
= 0.042.
This study identified novel druggable targets and similarities in mutational signatures between PSCC and HNSC with potential clinical implications.
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Thymic epithelial tumors (TETs) are one of the rarest adult malignancies. Among TETs, thymoma is the most predominant, characterized by a unique association with autoimmune diseases, followed by ...thymic carcinoma, which is less common but more clinically aggressive. Using multi-platform omics analyses on 117 TETs, we define four subtypes of these tumors defined by genomic hallmarks and an association with survival and World Health Organization histological subtype. We further demonstrate a marked prevalence of a thymoma-specific mutated oncogene, GTF2I, and explore its biological effects on multi-platform analysis. We further observe enrichment of mutations in HRAS, NRAS, and TP53. Last, we identify a molecular link between thymoma and the autoimmune disease myasthenia gravis, characterized by tumoral overexpression of muscle autoantigens, and increased aneuploidy.
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•Multi-omics definition of four robust molecular TET subtypes associated with survival•Thymomas have the lowest mutational burden among adult cancers•Enrichment of HRAS, NRAS, TP53, and recurrent GTF2I mutations are observed•Expression of autoimmune targets and aneuploidy links thymoma to myasthenia gravis
Radovich et al. perform multi-platform analyses of thymic epithelial tumors. They identify high prevalence of GTF2I mutations and enrichment of mutations in HRAS, NRAS, and TP53 and link overexpression of muscle autoantigens and increased aneuploidy in thymoma and patients' risk of having myasthenia gravis.
Oral premalignant lesions (OPLs) are the precursors to oral cavity cancers, and have variable rates of progression to invasive disease. As an intermediate state, OPLs have acquired a subset of the ...genomic alterations while arising in an oral inflammatory environment. These specific genomic changes may facilitate the transition to an immune microenvironment that permits malignant transformation. Here, we will discuss mechanisms by which OPLs develop an immunosuppressive microenvironment that facilitates progression to invasive cancer. We will describe how genomic alterations and immune microenvironmental changes co-evolve and cooperate to promote OSCC progression. Finally, we will describe how these immune microenvironmental changes provide specific and unique evolutionary vulnerabilities for targeted therapies. Therefore, understanding the genomic changes that drive immunosuppressive microenvironments may eventually translate into novel biomarker and/or therapeutic approaches to limit the progression of OPLs to potential lethal oral cancers.
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