A Multifunctionalized Potyvirus-Derived Nanoparticle That Targets and Internalizes into Cancer Cells.

Plant viral nanoparticles (VNPs) are attractive to nanomedicine researchers because of their safety, ease of production, resistance, and straightforward functionalization. In this paper, we developed and successfully purified a VNP derived from turnip mosaic virus (TuMV), a well-known plant pathogen, that exhibits a high affinity for immunoglobulins G (IgG) thanks to its functionalization with the Z domain of staphylococcal Protein A via gene fusion. We selected cetuximab as a model IgG to demonstrate the versatility of this novel TuMV VNP by developing a fluorescent nanoplatform to mark tumoral cells from the Cal33 line of a tongue squamous cell carcinoma. Using confocal microscopy, we observed that fluorescent VNP-cetuximab bound selectively to Cal33 and was internalized, revealing the potential of this nanotool in cancer research.

Novel Mouse Cell Lines and In Vivo Models for Human High-Grade Neuroendocrine Lung Carcinoma, Small Cell Lung Carcinoma (SCLC), and Large Cell Neuroendocrine Carcinoma (LCNEC).

There is a clear need to expand the toolkit of adequate mouse models and cell lines available for preclinical studies of high-grade neuroendocrine lung carcinoma (small cell lung carcinoma (SCLC) and large cell neuroendocrine carcinoma (LCNEC)). SCLC and LCNEC are two highly aggressive tumor types with dismal prognoses and few therapeutic options. Currently, there is an extreme paucity of material, particularly in the case of LCNEC. Given the lack of murine cell lines and transplant models of LCNEC, the need is imperative. In this study, we generated and examined new models of LCNEC and SCLC transplantable cell lines derived from our previously developed primary mouse LCNEC and SCLC tumors. RNA-seq analysis demonstrated that our cell lines and syngeneic tumors maintained the transcriptome program from the original transgenic primary tumor and displayed strong similarities to human SCLC or LCNEC. Importantly, the SCLC transplanted cell lines showed the ability to metastasize and mimic this characteristic of the human condition. In summary, we generated mouse cell line tools that allow further basic and translational research as well as preclinical testing of new treatment strategies for SCLC and LCNEC. These tools retain important features of their human counterparts and address the lack of LCNEC disease models.

Development of a mouse model for spontaneous oral squamous cell carcinoma in Fanconi anemia.

Fanconi anemia (FA) patients frequently develop oral squamous cell carcinoma (OSCC). This cancer in FA patients is diagnosed within the first 3-4 decades of life, very often preceded by lesions that suffer a malignant transformation. In addition, they respond poorly to current treatments due to toxicity or multiple recurrences. Translational research on new chemopreventive agents and therapeutic strategies has been unsuccessful partly due to scarcity of disease models or failure to fully reproduce the disease. Here we report that Fanca gene knockout mice (Fanca-/-) frequently display pre-malignant lesions in the oral cavity. Moreover, when these animals were crossed with animals having conditional deletion of Trp53 gene in oral mucosa (K14cre;Trp53F2-10/F2-10), they spontaneously developed OSCC with high penetrance and a median latency of less than ten months. Tumors were well differentiated and expressed markers of squamous differentiation, such as keratins K5 and K10. In conclusion, Fanca and Trp53 genes cooperate to suppress oral cancer in mice, and Fanca-/-;K14cre;Trp53F2-10/F2-10 mice constitute the first animal model of spontaneous OSCC in FA.

Pten and p53 Loss in the Mouse Lung Causes Adenocarcinoma and Sarcomatoid Carcinoma.

Lung cancer remains the leading cause of cancer deaths worldwide. Among the Non-Small Cell Carcinoma (NSCLC) category, Adenocarcinoma (ADC) represents the most common type, with different reported driver mutations, a bunch of models described and therapeutic options. Meanwhile, Pulmonary Sarcomatoid Carcinoma (PSC) is one of the rarest, with very poor outcomes, scarce availability of patient material, no effective therapies and no models available for preclinical research. Here, we describe that the combined deletion of Pten and Trp53 in the lungs of adult conditional mice leads to the development of both ADC and PSC irrespective of the lung targeted cell type after naphthalene induced airway epithelial regeneration. Although this model shows long latency periods and incomplete penetrance for tumor development, it is the first PSC mouse model reported so far, and sheds light on the relationships between ADC and PSC and their cells of origin. Moreover, human ADC show strong transcriptomic similarities to the mouse PSC, providing a link between both tumor types and the human ADC.

Hippo-YAP signaling activation and cross-talk with PI3K in oral cancer: A retrospective cohort study.

OBJECTIVES: This study aimed to investigate the clinical and prognostic relevance of the Hippo-YAP transactivators YAP1 and TAZ in oral squamous cell carcinoma, and their possible relationship with PI3K/mTOR pathway activation. MATERIALS AND METHODS: Immunohistochemical analysis of YAP1, TAZ, PIK3CA (p110α), p-AKT (Ser473), and p-S6 (Ser235) was performed in paraffin-embedded tissue specimens from 165 OSCC patients. Correlations between protein expression and clinical data were further assessed. RESULTS: YAP1 expression was detected in both cytoplasm and nucleus of tumor cells, whereas TAZ expression was only found in the nucleus. Nuclear YAP1 was significantly associated with tumor size (p = 0.03), neck lymph node metastasis (p = 0.02), TNM stage (p = 0.02), and poor differentiation (p = 0.04). Nuclear TAZ was associated with tobacco (p = 0.03) and alcohol consumption (p = 0.04), and poor tumor differentiation (p = 0.04). There was a positive significant correlation between nuclear and cytoplasmic YAP1, nuclear TAZ, p110α expression, and mTORC1 activation p-S6 (S235). Combined expression of nuclear and cytoplasmic YAP1 was prognostic in both univariate and multivariate analyses. Active nuclear YAP1 was significantly and independently associated with poor disease-specific (p = 0.005, HR = 2.520; 95% CI = 1.319-4.816) and overall survival (p = 0.015, HR = 2.126; 95% CI = 1.155-3.916). CONCLUSION: Nuclear YAP1 is an independent predictor of poor survival in oral squamous cell carcinoma.

Antitumor applications of polyphenol-conjugated turnip mosaic virus-derived nanoparticles.

Background: Filamentous plant virus-derived nanoparticles are biodegradable and noninfectious to humans. Their structure is also amenable to chemical modifications. They constitute an appealing material for biomedical applications including imaging and drug delivery. We had previously used turnip mosaic virus-derived nanoparticles (TuMV-NPs) to increase antibody-sensing in vivo, to prevent biofilm formation and to build biological nanoscaffolds. Materials & methods: We analyzed TuMV-NP biodistribution and tumor homing using in vivo imaging. We studied in vitro the interaction with human cancer cell lines and the antiproliferative effect of epigallocatechin gallate-functionalized TuMV-NPs. Results & conclusion: TuMV-NPs are efficiently internalized by human cells and show good tumor homing. The antiproliferative effect of epigallocatechin gallate-TuMV-NPs suggests that they could offer a potential anticancer therapy.

Cancer is the second leading cause of death worldwide, just behind cardiovascular disease. It accounts for nearly 10 million deaths annually, and new strategies to improve early detection and drug delivery are urgently needed. Nanoparticles are small structures within the nanometer range (1 billionth of a meter) that can be used to deliver either an imaging probe (tracer) to allow the detection of a tumor or drugs to kill tumor cells. There are many types of nanoparticles; those based on plant viruses are especially appealing for biomedical purposes because they are biodegradable and noninfectious to humans. Also, their physicochemical properties, such as symmetry, uniformity and loading capacity, make them excellent nanocarriers. We report here for the first time the ability of nanoparticles derived from the turnip mosaic virus (TuMV), a well-known virus naturally infecting cruciferous plants (e.g., broccoli, turnip, radish, cabbage) but not humans, to deliver a fluorescent imaging probe that allows tumor detection in vivo. Moreover, TuMV nanoparticles were used to deliver a natural chemotherapeutic agent of plant origin to different types of tumor cells (lung, colorectal, breast, and head and neck), showing increased antiproliferative capacity compared to the nonvehiculized drug.

Generating New FANCA-Deficient HNSCC Cell Lines by Genomic Editing Recapitulates the Cellular Phenotypes of Fanconi Anemia.

Fanconi anemia (FA) patients have an exacerbated risk of head and neck squamous cell carcinoma (HNSCC). Treatment is challenging as FA patients display enhanced toxicity to standard treatments, including radio/chemotherapy. Therefore, better therapies as well as new disease models are urgently needed. We have used CRISPR/Cas9 editing tools in order to interrupt the human FANCA gene by the generation of insertions/deletions (indels) in exon 4 in two cancer cell lines from sporadic HNSCC having no mutation in FA-genes: CAL27 and CAL33 cells. Our approach allowed efficient editing, subsequent purification of single-cell clones, and Sanger sequencing validation at the edited locus. Clones having frameshift indels in homozygosis did not express FANCA protein and were selected for further analysis. When compared with parental CAL27 and CAL33, FANCA-mutant cell clones displayed a FA-phenotype as they (i) are highly sensitive to DNA interstrand crosslink (ICL) agents such as mitomycin C (MMC) or cisplatin, (ii) do not monoubiquitinate FANCD2 upon MMC treatment and therefore (iii) do not form FANCD2 nuclear foci, and (iv) they display increased chromosome fragility and G2 arrest after diepoxybutane (DEB) treatment. These FANCA-mutant clones display similar growth rates as their parental cells. Interestingly, mutant cells acquire phenotypes associated with more aggressive disease, such as increased migration in wound healing assays. Therefore, CAL27 and CAL33 cells with FANCA mutations are phenocopies of FA-HNSCC cells.

Genes involved in the epithelial-mesenchymal transition in oral cancer: A systematic review.

OBJECTIVE: Epithelial-mesenchymal transition (EMT) is considered the initial step in the invasion-metastasis cascade. The aim of this systematic review was to study the signature of genes involved in the EMT process in oral cancer (OC) confirmed by protein expression and its possible relationship with oral squamous cell carcinoma (OSCC) prognostic variables. MATERIALS AND METHODS: A search of the scientific literature was carried out with no start date restriction until 17 September 2020 in the electronic databases Pubmed/MEDLINE, Web of Science, Cochrane Library and Scopus, following specific eligibility criteria. The methodological quality of the included studies was assessed using the Newcastle-Ottawa tool. RESULTS: A total of 8 retrospective cohort studies were included, all of them performed in China and with low risk of bias. Overexpression of the genes HNRNPC, ITGA5, HMGA2 and SRSF3, and low expression of ALDH3A1 and ARID2 promote EMT in OC. The more advanced clinical stages of the TNM classification were significantly associated with overexpression of HNRNPC, ITGA5, HMGA2 and SRSF3, and low expression of ARID2. CONCLUSIONS: HNRNPC, ITGA5, HMGA2, SRSF3, ALDH3A1 and ARID2 genes were associated with EMT process. Over- or under-expression of these genes is associated with worse stages of OSCC and/or worse prognosis of the tumor. Further studies on this topic are needed in different countries to be able to confirm these results, since the detection of these genes can help to know which tumors have a worse prognosis.

Neuroendocrine Lung Cancer Mouse Models: An Overview.

Neuroendocrine lung tumors comprise a range of malignancies that extend from benign tumorlets to the most prevalent and aggressive Small Cell Lung Carcinoma (SCLC). They also include low-grade Typical Carcinoids (TC), intermediate-grade Atypical Carcinoids (AC) and high-grade Large Cell Neuroendocrine Carcinoma (LCNEC). Optimal treatment options have not been adequately established: surgical resection when possible is the choice for AC and TC, and for SCLC chemotherapy and very recently, immune checkpoint inhibitors. Some mouse models have been generated based on the molecular alterations identified in genomic analyses of human tumors. With the exception of SCLC, there is a limited availability of (preclinical) models making their development an unmet need for the understanding of the molecular mechanisms underlying these diseases. For SCLC, these models are crucial for translational research and novel drug testing, given the paucity of human material from surgery. The lack of early detection systems for lung cancer point them out as suitable frameworks for the identification of biomarkers at the initial stages of tumor development and for testing molecular imaging methods based on somatostatin receptors. Here, we review the relevant models reported to date, their impact on the understanding of the biology of the tumor subtypes and their relationships, as well as the effect of the analyses of the genetic landscape of the human tumors and molecular imaging tools in their development.

Competitive Repopulation Assay of Long-Term Epidermal Stem Cell Regeneration Potential.

Epidermal stem cells are responsible for normal tissue homeostasis and contribute to tissue regeneration during injury. Several assays measuring stem cell frequency and function can be used to assess epidermal stem cell potential. However, the ultimate assay that accounts for stemness is the capacity to sustain in vivo long-term tissue regeneration and maintenance. We can use this type of analysis to interrogate whether a specific genetic alteration (e.g., activation or inactivation of any gene thought to be involved in stem cell quiescence or proliferation) confers increased or decreased stem cell potential.

Hippo Pathway and YAP Signaling Alterations in Squamous Cancer of the Head and Neck.

Head and neck cancer affects the upper aerodigestive tract and is the sixth leading cancer worldwide by incidence and the seventh by cause of death. Despite significant advances in surgery and chemotherapy, molecularly targeted therapeutic options for this type of cancer are scarce and long term survival rates remain low. Recently, comprehensive genomic studies have highlighted the most commonly altered genes and signaling pathways in this cancer. The Hippo-YAP pathway has been identified as a key oncogenic pathway in multiple tumors. Expression of genes controlled by the Hippo downstream transcriptional coactivators YAP (Yes-associated protein 1) and TAZ (WWTR1, WW domain containing transcription regulator 1) is widely deregulated in human cancer including head and neck squamous cell carcinoma (HNSCC). Interestingly, YAP/TAZ signaling might not be as essential for the normal homeostasis of adult tissues as for oncogenic growth, altogether making the pathway an amenable therapeutic target in cancer. Recent advances in the role of Hippo-YAP pathway in HNSCC have provided evidence that genetic alterations frequent in this type of cancer such as PIK3CA (phosphatidylinositide 3-kinase catalytic subunit alpha) overexpression or FAT1 (FAT atypical cadherin 1) functional loss can result in YAP activation. We discuss current therapeutic options targeting this pathway which are currently in use for other tumor types.

Differential development of large-cell neuroendocrine or small-cell lung carcinoma upon inactivation of 4 tumor suppressor genes.

High-grade neuroendocrine lung malignancies (large-cell neuroendocrine cell carcinoma, LCNEC, and small-cell lung carcinoma, SCLC) are among the most deadly lung cancer conditions with no optimal clinical management. The biological relationships between SCLC and LCNEC are still largely unknown and a current matter of debate as growing molecular data reveal high heterogeneity with potential therapeutic consequences. Here we describe murine models of high-grade neuroendocrine lung carcinomas generated by the loss of 4 tumor suppressors. In an Rbl1-null background, deletion of Rb1, Pten, and Trp53 floxed alleles after Ad-CMVcre infection in a wide variety of lung epithelial cells produces LCNEC. Meanwhile, inactivation of these genes using Ad-K5cre in basal cells leads to the development of SCLC, thus differentially influencing the lung cancer type developed. So far, a defined model of LCNEC has not been reported. Molecular and transcriptomic analyses of both models revealed strong similarities to their human counterparts. In addition, a 68Ga-DOTATOC-based molecular-imaging method provides a tool for detection and monitoring the progression of the cancer. These data offer insight into the biology of SCLC and LCNEC, providing a useful framework for development of compounds and preclinical investigations in accurate immunocompetent models.

Frequent Alteration of Annexin A9 and A10 in HPV-Negative Head and Neck Squamous Cell Carcinomas: Correlation with the Histopathological Differentiation Grade.

The annexin protein superfamily has been implicated in multiple physiological and pathological processes, including carcinogenesis. Altered expression of various annexins has frequently been observed and linked to the development and progression of various human malignancies. However, information is lacking on the expression and clinical significance of annexin A9 (ANXA9) and A10 (ANXA10) in head and neck squamous cell carcinomas (HNSCC). ANXA9 and ANXA10 expression was evaluated in a large cohort of 372 surgically treated HPV-negative HNSCC patients and correlated with the clinicopathologic parameters and disease outcomes. Down-regulation of ANXA9 expression was found in 42% of HNSCC tissue samples, compared to normal epithelia. ANXA9 expression in tumors was significantly associated with oropharyngeal location and histological differentiation grade (P < 0.001). In marked contrast, ANXA10 expression was absent in normal epithelium, but variably detected in the cytoplasm of cancer cells. Positive ANXA10 expression was found in 64% of tumors, and was significantly associated with differentiation grade (P < 0.001), being also more frequent in oropharyngeal tumors (P = 0.019). These results reveal that the expression of both ANXA9 and ANXA10 is frequently altered in HNSCC and associated to the tumor differentiation grade, suggesting that they could be implicated in the pathogenesis of these cancers.

CDK4/6 Inhibitor as a Novel Therapeutic Approach for Advanced Bladder Cancer Independently of RB1 Status.

PURPOSE: Bladder cancer is a clinical and social problem due to its high incidence and recurrence rates. It frequently appears in elderly patients showing other medical comorbidities that hamper the use of standard chemotherapy. We evaluated the activity of CDK4/6 inhibitor as a new therapy for patients unfit for cisplatin (CDDP). EXPERIMENTAL DESIGN: Bladder cancer cell lines were tested for in vitro sensitivity to CDK4/6 inhibition. A novel metastatic bladder cancer mouse model was developed and used to test its in vivo activity. RESULTS: Cell lines tested were sensitive to CDK4/6 inhibition, independent on RB1 gene status. Transcriptome analyses and knockdown experiments revealed a major role for FOXM1 in this response. CDK4/6 inhibition resulted in reduced FOXM1 phosphorylation in vitro and in vivo and showed synergy with CDDP, allowing a significant tumor regression. FOXM1 exerted important oncogenic roles in bladder cancer. CONCLUSIONS: CDK4/6 inhibitors, alone or in combination, are a novel therapeutic strategy for patients with advanced bladder cancer previously classified as unfit for current treatment options.

The transcriptional co-activator YAP: A new player in head and neck cancer.

The Hippo-YAP (Yes-associated protein) pathway is a key regulator of tissue growth, organ size and stem cell function. More recently, a fundamental role for this pathway has emerged in stem cell function and tumorigenesis. Activation of the transcriptional co-activator YAP promotes cell-contact independent proliferation, epithelial to mesenchymal transition (EMT), cancer stem cell features and drug resistance. In this review, we describe the main components of the pathway, the microenvironment and the cell-intrinsic cues governing its activation, the downstream players of the pathway and the biological implications of their activation in the context of cancer. We will focus on the existing knowledge of this pathway in head and neck squamous carcinoma (HNSCC), its clinical value in this type of cancer as a marker of poor prognosis and resistance to therapy, as well as the most encouraging therapeutic strategies targeting the pathway.

Bosutinib Inhibits EGFR Activation in Head and Neck Cancer.

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide, and although new therapeutic approaches have been recently evaluated, overall patient survival is still poor. Thus, new effective and selective clinical treatments are urgently needed. An analysis of data from large-scale, high-throughput drug screening cell line projects identified Bosutinib, a Src/Abl inhibitor that is currently used for the treatment of chronic myelogenous leukemia, as a candidate drug to treat HNSCC. Using a panel of HNSCC-derived cell lines, we found that treatment with Bosutinib reduced cell proliferation and induced apoptosis of sensitive cell lines. The drug rapidly inhibited Src and EGFR (epidermal growth factor receptor) phosphorylation, and sensitivity to Bosutinib was correlated with the activation status of EGFR. Similar findings were observed in in vivo xenograft assays using HNSCC derived cells. Moreover, in the presence of mutations in PIK3CA, the combination of Bosutinib with the PI3Kα inhibitor Alpelisib showed a synergistic effect. These results suggest that Bosutinib could be a new effective drug for the treatment of HNSCC, particularly in tumors with high EGFR activity. Its combination with Alpelisib could especially benefit patients bearing activating mutations of PIK3CA.

Overexpression of PIK3CA in head and neck squamous cell carcinoma is associated with poor outcome and activation of the YAP pathway.

OBJECTIVES: Phosphatidylinositol 3-kinase catalytic subunit alpha (PIK3CA) is commonly altered in many human tumors, leading to the activation of p110α enzymatic activity that stimulates growth factor-independent cell growth. PIK3CA alterations such as mutation, gene amplification and overexpression are common in head and neck squamous cell carcinoma (HNSCC) and. We aim to explore how these alterations and clinical outcome are associated, as well as the molecular mechanisms involved. MATERIAL AND METHODS: Mutation and copy-number variation in PIK3CA, and whole-genome expression profiles, were analyzed in primary HNSCC tumors from The Cancer Genome Atlas (TCGA) cohort (n = 243). The results were validated in an independent cohort form the University Hospital of A Coruña (UHAC, n = 62). Expression of the PIK3CA gene protein product (PI3K p110α) and nuclear YAP were assessed in tissue microarrays in a cohort from the University Hospital 12 de Octubre (UH12O, n = 91). RESULTS: Only high expression of the PIK3CA gene was associated with poor clinical outcome. The study of gene expression, transcription factor and protein signatures suggested that the activation of the Hippo-YAP pathway, involved in organ size, stem cell maintenance and tumorigenesis, could underlie tumor progression in PI3KCA overexpressing tumors. Tissue arrays showed that PI3K p110α levels correlated with YAP nuclear localization in HNSCC tumors. CONCLUSIONS: High expression of PIK3CA in HNSCC primary tumors identifies patients at high risk for recurrence. In these tumors, progression could rely on the Hippo-YAP pathway instead of the canonical Akt/mTOR pathway. This observation could have important implications in the therapeutic options for patients.

Inefficient differentiation response to cell cycle stress leads to genomic instability and malignant progression of squamous carcinoma cells.

Squamous cell carcinoma (SCC) or epidermoid cancer is a frequent and aggressive malignancy. However in apparent paradox it retains the squamous differentiation phenotype except for very dysplastic lesions. We have shown that cell cycle stress in normal epidermal keratinocytes triggers a squamous differentiation response involving irreversible mitosis block and polyploidisation. Here we show that cutaneous SCC cells conserve a partial squamous DNA damage-induced differentiation response that allows them to overcome the cell division block. The capacity to divide in spite of drug-induced mitotic stress and DNA damage made well-differentiated SCC cells more genomically instable and more malignant in vivo. Consistently, in a series of human biopsies, non-metastatic SCCs displayed a higher degree of chromosomal alterations and higher expression of the S phase regulator Cyclin E and the DNA damage signal γH2AX than the less aggressive, non-squamous, basal cell carcinomas. However, metastatic SCCs lost the γH2AX signal and Cyclin E, or accumulated cytoplasmic Cyclin E. Conversely, inhibition of endogenous Cyclin E in well-differentiated SCC cells interfered with the squamous phenotype. The results suggest a dual role of cell cycle stress-induced differentiation in squamous cancer: the resulting mitotic blocks would impose, when irreversible, a proliferative barrier, when reversible, a source of genomic instability, thus contributing to malignancy.

IKKß-Mediated Resistance to Skin Cancer Development Is Ink4a/Arf-Dependent.

IKKß (encoded by IKBKB) is a protein kinase that regulates the activity of numerous proteins important in several signaling pathways, such as the NF-κB pathway. IKKß exerts a protumorigenic role in several animal models of lung, hepatic, intestinal, and oral cancer. In addition, genomic and proteomic studies of human tumors also indicate that IKBKB gene is amplified or overexpressed in multiple tumor types. Here, the relevance of IKKß in skin cancer was determined by performing carcinogenesis studies in animal models overexpressing IKKß in the basal skin layer. IKKß overexpression resulted in a striking resistance to skin cancer development and an increased expression of several tumor suppressor proteins, such as p53, p16, and p19. Mechanistically, this skin tumor-protective role of IKKß is independent of p53, but dependent on the activity of the Ink4a/Arf locus. Interestingly, in the absence of p16 and p19, IKKß-increased expression favors the appearance of cutaneous spindle cell-like squamous cell carcinomas, which are highly aggressive tumors. These results reveal that IKKß activity prevents skin tumor development, and shed light on the complex nature of IKKß effects on cancer progression, as IKKß can both promote and prevent carcinogenesis depending on the cell type or molecular context.Implications: The ability of IKKß to promote or prevent carcinogenesis suggests the need for further evaluation when targeting this protein. Mol Cancer Res; 15(9); 1255-64. ©2017 AACR.