A deep learning model to predict Ki-67 positivity in oral squamous cell carcinoma

Anatomical pathology is undergoing its third revolution, transitioning from analogical to digital pathology and incorporating new artificial intelligence technologies into clinical practice. Aside from classification, detection, and segmentation models, predictive models are gaining traction since they can impact diagnostic processes and laboratory activity, lowering consumable usage and turnaround time. Our research aimed to create a deep-learning model to generate synthetic Ki-67 immunohistochemistry from Haematoxylin and Eosin (H&E) stained images. We used 175 oral squamous cell carcinoma (OSCC) from the University Federico II's Pathology Unit's archives to train our model to generate 4 Tissue Micro Arrays (TMAs). We sectioned one slide from each TMA, first stained with H&E and then re-stained with anti-Ki-67 immunohistochemistry (IHC). In digitised slides, cores were disarrayed, and the matching cores of the 2 stained were aligned to construct a dataset to train a Pix2Pix algorithm to convert H&E images to IHC. Pathologists could recognise the synthetic images in only half of the cases in a specially designed likelihood test. Hence, our model produced realistic synthetic images. We next used QuPath to quantify IHC positivity, achieving remarkable levels of agreement between genuine and synthetic IHC. Furthermore, a categorical analysis employing 3 Ki-67 positivity cut-offs (5%, 10%, and 15%) revealed high positive-predictive values. Our model is a promising tool for collecting Ki-67 positivity information directly on H&E slides, reducing laboratory demand and improving patient management. It is also a valuable option for smaller laboratories to easily and quickly screen bioptic samples and prioritise them in a digital pathology workflow.

Immunohistochemical expression of PRAME is a marker of poor prognosis in uveal melanoma: A clinico-pathologic and immunohistochemical study on a series of 85 cases

PReferentially expressed Antigen in Melanoma (PRAME) is a cancer testis antigen, first isolated in tumor-reactive T-cell clones from a metastatic melanoma patient. It has been widely studied in skin pathology as an immunohistochemical marker capable of distinguishing between benign nevi and malignant melanomas. PRAME has been found to be also expressed in non-melanocytic tumors, including lung, breast, kidney and ovarian cancer. However, less is known about the diagnostic and/or prognostic role of this protein in uveal melanoma (UM); few studies have reported that PRAME expression seems to give to UM patients an additional metastatic risk beyond the other already-known prognostic parameters. In the present retrospective study, we aimed to correlate PRAME immunoreactivity to other clinico-pathologic features and follow-up data on a large series of 85 cases (45 non-metastasizing and 40 metastasizing tumors) of primary UM. A statistically significant correlation was found between PRAME expression and higher metastatic risk and lower metastasis-free survival. We propose to include PRAME in the immunohistochemical panel of UM as an easily usable marker capable of predicting higher metastatic risk and stratifying patients' outcome.

Neuropilin-1 Expression Associates with Poor Prognosis in HNSCC and Elicits EGFR Activation upon CDDP-Induced Cytotoxic Stress

Head and neck squamous cell carcinoma (HNSCC) includes a group of aggressive malignancies characterized by the overexpression of the epidermal growth factor receptor (EGFR) in 90% of cases. Neuropilin-1 (NRP-1) acts as an EGFR co-receptor, enhancing, upon ligand stimulation, EGFR signaling in several cellular models. However, NRP-1 remains poorly characterized in HNSCC. By utilizing in vitro cellular models of HNSCC, we report that NRP-1 is involved in the regulation of EGFR signaling. In fact, NRP-1 can lead to cisplatin-induced EGFR phosphorylation, an escape mechanism activated by cancer cells upon cytotoxic stress. Furthermore, we evaluated Neuropilin-1 staining in tissue samples of an HNSCC case series (n = 218), unraveling a prognostic value for the Neuropilin-1 tissue expression. These data suggest a potential role for NRP-1 in HNSCC cancer progression, expanding the repertoire of signaling in which NRP-1 is involved and eliciting the need for further investigations on NRP-1 as a suitable target for HNSCC novel therapeutic approaches.

Tissue Expression of Carbonic Anhydrase IX Correlates to More Aggressive Phenotype of Basal Cell Carcinoma

Basal cell carcinoma (BCC) is the most common cancer in the white-skinned population accounting for about 15% of all neoplasms. Its incidence is increasing worldwide, at a rate of about 10% per year. BCC, although infrequently metastasizing, very often causes extensive tissue losses, due to the high propensity toward stromal infiltration, particularly in its dedifferentiated forms, with disfiguring and debilitating results. To date, there still is limited availability of therapeutic treatments alternative to surgery. We evaluated the immunohistochemical expression of the carbonic anhydrase IX (CAIX), one of the main markers of tissue hypoxia, in a set of 85 archived FFPE BCC tissues, including the main subtypes, with different clinical outcomes, to demonstrate a possible relationship between hypoxic phenotype and biological aggressiveness of these neoplasms. Our results showed that the expression level of the CAIX protein contributes to the stratification of BCC in the different risk classes for recurrence. We hypothesize for CAIX a potential therapeutic role as a target therapy in the treatment of more aggressive BCCs, thus providing an alternative to surgical and pharmacological therapy with Hedgehog inhibitors, a promising example of target therapy in BCCs.

Low-Grade Intraductal Carcinoma of the Parotid Gland: A Case Report and Literature Review

Low-grade intraductal carcinoma is a rare neoplasia with an excellent prognosis, previously classified as low-grade cribriform cystadenocarcinoma and low-grade salivary duct carcinoma. The tumor mainly occurs in the parotid gland and presents a ductal phenotype and an intraductal/intracystic growth pattern. It resembles intraductal breast lesions such as atypical ductal hyperplasia, papillary and cribriform ductal carcinoma in situ. Despite its infrequency, discriminating low-grade intraductal carcinoma from other salivary gland tumors is crucial, especially because of its favorable prognosis. A 74-year-old woman with a history of neurofibromatosis underwent a superficial parotidectomy to remove a sharply demarcated multi-cystic mass, diagnosed as category 4 at FNAC. The histological examination revealed a demarcated but unencapsulated lesion composed of a bigger cyst surrounded by several smaller cysts, lined by a monolayer or bilayer epithelium alternated with a cribriform proliferation, characterized by "Roman-bridges", with occasional micro-papillae. A myoepithelial component, with a basal disposition, was present, confirmed by intense staining for protein p63 and SMA. Immunohistochemical stains showed intense, strong uniform positivity for pan-cytokeratin, protein S100, and SOX10. The Ki67 proliferation index was low (< 10%). A diagnosis of Low-grade Intraductal Carcinoma (LGIC) of the parotid was made. We performed a literature search in PUBMED for "Intraductal carcinoma", "Low-grade Intraductal Carcinoma", "Cribriform Cystadenocarcinoma", "Salivary Duct Carcinoma", and "Low-Grade Salivary Duct Carcinoma". We selected 17 papers published between 1983 and 2020; the most affected anatomical site was the parotid gland (77/90), followed by minor salivary glands (6/90), the intraparotid lymph nodes (3/90) and the submandibular gland (4/90). Their main histopathological features are reported in the paper. Here we present a case report and a review of scientific literature on this topic to provide some essential diagnostic tools to discriminate this rare entity.

Retraction Note: Critical role of CCDC6 in the neoplastic growth of testicular germ cell tumors

This article has been retracted. Please see the Retraction Notice for more detail: https://doi.org/10.1186/1471-2407-13-433.

Expression of P16INK4a in Uveal Melanoma: New Perspectives

Uveal melanoma (UM) is the most common intraocular tumor in adults. Despite sharing the name and similar morphological features with cutaneous melanoma (CM), it is an entirely different neoplasia with a particular genetic background and clinical behavior. CDKN2A is a gene located at chromosome 9p21, encoding for P16INK4a and P14(ARF) proteins, whose role as a tumor suppressor has been clearly defined in many malignant tumors. CDKN2A frequently presents germline mutations in familial CM and epigenetic downregulation in a considerable percentage of sporadic CM. It has been hypothesized that CDKN2A alterations are early events in CM development, playing a central role in the malignant transformation of melanocytes. Alterations of the CDKN2A gene reduce the expression of P16INK4a in most CM subtypes. Immunohistochemical evaluation of P16INK4a is currently used, in association with Ki67 and HMB45, in pathology practice to discriminate between dysplastic nevi and melanoma. On the other hand, CKDN2A is rarely mutated in UM, and the immunohistochemical expression of P16INK4a has only been reported in small case series. We tested P16INK4a expression on paraffin-embedded tissue sections from 9 tissue microarrays (TMAs), built with 2 mm cores derived from 133 uveal melanoma FFPE blocks, collected from 1990 to 2018, and from selected paraffin-blocks of 3 UM liver metastases. The immunohistochemical expression of P16INK4a was assessed with a visual evaluation by light microscopy and then with a digital approach. Both approaches, with an acceptable concordance rate, revealed P16INK4a expression in a large proportion of UM cases and all liver metastases, opening new possibilities of using it in the differential diagnosis between cutaneous and uveal melanoma metastases in cases of unknown primary tumor or patients with two different primary melanomas.

A Machine-learning Approach for the Assessment of the Proliferative Compartment of Solid Tumors on Hematoxylin-Eosin-Stained Sections

We introduce a machine learning-based analysis to predict the immunohistochemical (IHC) labeling index for the cell proliferation marker Ki67/MIB1 on cancer tissues based on morphometrical features extracted from hematoxylin and eosin (H&E)-stained formalin-fixed, paraffin-embedded (FFPE) tumor tissue samples. We provided a proof-of-concept prediction of the Ki67/MIB1 IHC positivity of cancer cells through the definition and quantitation of single nuclear features. In the first instance, we set our digital framework on Ki67/MIB1-stained OSCC (oral squamous cell carcinoma) tissue sample whole slide images, using QuPath as a working platform and its integrated algorithms, and we built a classifier in order to distinguish tumor and stroma classes and, within them, Ki67-positive and Ki67-negative cells; then, we sorted the morphometric features of tumor cells related to their Ki67 IHC status. Among the evaluated features, nuclear hematoxylin mean optical density (NHMOD) presented as the best one to distinguish Ki67/MIB1 positive from negative cells. We confirmed our findings in a single-cell level analysis of H&E staining on Ki67-immunostained/H&E-decolored tissue samples. Finally, we tested our digital framework on a case series of oral squamous cell carcinomas (OSCC), arranged in tissue microarrays; we selected two consecutive sections of each OSCC FFPE TMA (tissue microarray) block, respectively stained with H&E and immuno-stained for Ki67/MIB1. We automatically detected tumor cells in H&E slides and generated a “false color map” (FCM) based on NHMOD through the QuPath measurements map tool. FCM nearly coincided with the actual immunohistochemical result, allowing the prediction of Ki67/MIB1 positive cells in a direct visual fashion. Our proposed approach provides the pathologist with a fast method of identifying the proliferating compartment of the tumor through a quantitative assessment of the nuclear features on H&E slides, readily appreciable by visual inspection. Although this technique needs to be fine-tuned and tested on larger series of tumors, the digital analysis approach appears to be a promising tool to quickly forecast the tumor’s proliferation fraction directly on routinely H&E-stained digital sections.

Erratum: Epigenetics of oral and oropharyngeal cancers (Review)

[This corrects the article DOI: 10.3892/br.2018.1136.].

Thyroid hormone induces progression and invasiveness of squamous cell carcinomas by promoting a ZEB-1/E-cadherin switch

Epithelial tumor progression often involves epithelial-mesenchymal transition (EMT). We report that increased intracellular levels of thyroid hormone (TH) promote the EMT and malignant evolution of squamous cell carcinoma (SCC) cells. TH induces the EMT by transcriptionally up-regulating ZEB-1, mesenchymal genes and metalloproteases and suppresses E-cadherin expression. Accordingly, in human SCC, elevated D2 (the T3-producing enzyme) correlates with tumor grade and is associated with an increased risk of postsurgical relapse and shorter disease-free survival. These data provide the first in vivo demonstration that TH and its activating enzyme, D2, play an effective role not only in the EMT but also in the entire neoplastic cascade starting from tumor formation up to metastatic transformation, and supports the concept that TH is an EMT promoter. Our studies indicate that tumor progression relies on precise T3 availability, suggesting that pharmacological inactivation of D2 and TH signaling may suppress the metastatic proclivity of SCC.

Circulating miRNAs in Untreated Breast Cancer: An Exploratory Multimodality Morpho-Functional Study

The aim of this study was to identify new disease-related circulating miRNAs with high diagnostic accuracy for breast cancer (BC) and to correlate their deregulation with the morpho-functional characteristics of the tumour, as assessed in vivo by positron emission tomography/magnetic resonance (PET/MR) imaging. A total of 77 untreated female BC patients underwent same-day PET/MR and blood collection, and 78 healthy donors were recruited as negative controls. The expression profile of 84 human miRNAs was screened by using miRNA PCR arrays and validated by real-time PCR. The validated miRNAs were correlated with the quantitative imaging parameters extracted from the primary BC samples. Circulating miR-125b-5p and miR-143-3p were upregulated in BC plasma and able to discriminate BC patients from healthy subjects (miR-125-5p area under the receiver operating characteristic ROC curve (AUC) = 0.85 and miR-143-3p AUC = 0.80). Circulating CA15-3, a soluble form of the transmembrane glycoprotein Mucin 1 (MUC-1) that is upregulated in epithelial cancer cells of different origins, was combined with miR-125b-5p and improved the diagnostic accuracy from 70% (CA15-3 alone) to 89% (CA15-3 plus miR-125b-5p). MiR-143-3p showed a strong and significant correlation with the stage of the disease, apparent diffusion coefficient (ADCmean), reverse efflux volume transfer constant (Kepmean) and maximum standardized uptake value (SUVmax), and it might represent a biomarker of tumour aggressiveness. Similarly, miR-125b-5p was correlated with stage and grade 2 but inversely correlated with the forward volume transfer constant (Ktransmean) and proliferation index (Ki67), suggesting a potential role as a biomarker of a relatively more favourable prognosis. In situ hybridization (ISH) experiments revealed that miR-143-3p was expressed in endothelial tumour cells, miR-125-5p in cancer-associated fibroblasts, and neither in epithelial tumour cells. Our results suggested that miR-125-5p and miR-143-3p are potential biomarkers for the risk stratification of BC, and Kaplan-Maier plots confirmed this hypothesis. In addition, the combined use of miR-125-b-5p and CA15-3 enhanced the diagnostic accuracy up to 89%. This is the first study that correlates circulating miRNAs with in vivo quantified tumour biology through PET/MR biomarkers. This integration elucidates the link between the plasmatic increase in these two potential circulating biomarkers and the biology of untreated BC. In conclusion, while miR-143-3b and miR-125b-5p provide valuable information for prognosis, a combination of miR-125b-5p with the tumour marker CA15-3 improves sensitivity for BC detection, which warrants consideration by further validation studies.

CCDC6 and USP7 expression levels suggest novel treatment options in high-grade urothelial bladder cancer

Background

The muscle invasive form of urothelial bladder cancer (UBC) is a deadly disease. Currently, the therapeutic approach of UBC is mostly based on surgery and standard chemotherapy.

Biomarkers to establish appropriate drugs usage are missing. Deficiency of the tumor suppressor CCDC6 determines PARP-inhibitor sensitivity. The CCDC6 levels are modulated by the deubiquitinase USP7. In this work we scored CCDC6 and USP7 expression levels in primary UBC and we evaluated the expression levels of CCDC6 in correlation with the effects of the PARP-inhibitors combined with the USP7 inhibitor, P5091, in vitro. Since PARP-inhibitors could be enhanced by conventional chemotherapy or DNA damage inducers, we tested the new agent RRx-001, able to induce DNA damage, to prove the benefit of combined treatments in bladder cancer cells.

Methods

The J82, T24, 5637 and KU-19-19 bladder cancer cells were exposed to USP7 inhibitor P5091 in presence of cycloheximide to analyse the CCDC6 stability. Upon the CCDC6 degradation induced by P5091, the cells sensitivity to PARP-inhibitor was evaluated by cell viability assays. The ability of the DNA damage inducer RRx-001 to modulate CCDC6 protein levels and H2AX phosphorylation was detected at immunoblot. The combination of USP7 inhibitor plus RRx-001 enhanced the PARP-inhibitor sensitivity, as evaluated by cell viability assays. The results of the scores and correlation of CCDC6 and USP7 expression levels obtained by UBC primary biopsies staining were used to cluster patients by a K-mean cluster analysis.

Results

P5091 determining CCDC6 degradation promoted bladder cancer cells sensitivity to PARP-inhibitor drugs. RRx-001, by inducing DNA damage, enhanced the effects of the combined treatment. The immunohistochemical staining of both CCDC6 and USP7 proteins allowed to cluster the high grade (G3) UBC patients, on the basis of CCDC6 expression levels.

Conclusions

In high grade UBC the identification of two clusters of patients based on CCDC6 and USP7 expession can possibly indicate the use of PARP-inhibitor drugs, in combination with USP7 inhibitor in addition to the DNA damage inducer RRx-001, that also acts as an immunomodulatory agent, offering novel therapeutic strategy for personalized medicine in bladder cancer patients.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1087-1) contains supplementary material, which is available to authorized users.

Epigenetics of oral and oropharyngeal cancers

Oral and oropharyngeal cancers represent the two most common malignancies of the head and neck region. The major risk factors for these cancers include alcohol consumption, tobacco use (via smoking or chewing) and high-risk human papillomavirus infection. The transition from normal epithelium to premalignant tissue and finally carcinoma is in part caused by a summation of genetic and epigenetic modifications. Epigenetic refers to modifications in the way the genome is expressed in cells. The most common examples of epigenetic control of gene expression are DNA methylation, histone modification and regulation by small non-coding RNAs. The aim of the current paper was to review the recent studies on the main epigenetic changes that have been suggested to serve a role in the carcinogenesis process and progression of oral and oropharyngeal cancers. Furthermore, it is discussed how the epigenetic changes may be used as potential predictive biomarkers and how recent findings in the field may impact the personalized cancer therapy approach for these tumors.

An "ex vivo model" contributing to the diagnosis and evaluation of new drugs in cystic fibrosis

Cystic fibrosis (CF) is an autosomal recessive disease caused by mutations in the cystic fibrosis transmembrane regulator (CFTR) gene. About 2000 mutations have been described so far. We setup an ex vivo model of human nasal epithelial cells (HNECs) to study CF patients testing the effect of novel mutations and molecular therapies. We performed sampling (by brushing), followed by culture and analysis of HNECs using a series of molecular techniques. We performed 50 brushings from CF patients and controls. Using cultured cells, we: i) demonstrated the widely heterogeneous CFTR expression in patients and in controls; ii) defined the splicing effect of a CFTR mutation; iii) assessed the CFTR gating activity in patients bearing different mutations; iv) demonstrated that butyrate significantly enhances CFTR expression. Based on our data, we can conclude: 1) HNEC brushing is performed without anaesthesia and is well tolerated in all CF patients (children and adults); 2) HNECs can be preserved for up to 48 hours before culture allowings multicentre studies; 3) HNECs culture can be considered a suitable model to study the molecular effects of new CFTR gene mutations and/or uncertain meaning specific mutations of carriers; 4) an ex vivo model of HNECs may be used to evaluate, before human use, the effect of new drugs on patients’ cells bearing specific CFTR mutations; 5) the methodology is adequate for a quantitative measurement, by fluorescence, of the CFTR gating activity of the HNECs from patients with different genotypes identifying: a) CF patients bearing two severe mutations with an activity < 10% (compared to controls – 100%); b) CF patients bearing at least a mild mutation with an activity of 10-20%; c) CF carriers (heterozygous subjects) with an activity between 40-70%.

Intraretinal changes in idiopathic versus diabetic epiretinal membranes after macular peeling

Introduction

Epiretinal traction is not responsible only for epiretinal but also intraretinal changes. This study aims to describe structural and vascular intraretinal changes after macular peeling in idiopathic (iERM) vs diabetic ERM (dERM).

Methods

We conducted a prospective interventional study on forty-two eyes, 23 with iERMs and 19 with dERMs, undergoing ERM-ILM peeling. We performed SD-OCT preoperatively, 1 and 6 months postoperatively to assess central macular thickness (CMT), intraretinal cysts (IC) and/or continuous ectopic inner foveal layers (CEIFL), superficial and deep capillary free zone (CFZ) area on OCT-A. Glial fibrillary acidic protein (GFAP), as a Müller cells marker, was detected immunohistochemically on ILM specimens, to assess Müller cells iatrogenic damage.

Results

The CEIFLs were significantly more common in iERMs (12 (52.2%) in iERMs vs 2 (10.5%) in dERMs, p = 0.004), whereas ICs in dERMs (6 (26.1%) in iERMs vs 17 (89.5%) in dERMs, p<0.001). Median preoperative and postoperative BCVA was 20/50 [20/40-20/66] and 20/33 [20/25-20/40] in iERMs and 20/100 [20/66-20/200] and 20/50 [20/50-20/66] in dERMs, respectively. Median preoperative and postoperative CMT was 423 [370–488] and 364 [329–382] μm in iERM group and 465 [447–503] and 378 [359–433] μm in dERM group, respectively. The BCVA improvement and reduction of CMT thickness were significant in both groups (p<0.001). The presence of CEIFL was associated with lower BCVA in iERMs. Deep CFZ network significantly increased only in dERMs, passing from 0.34 [0.29–0.42] mm² preoperatively to 0.56 [0.46–0.6] mm² at 6-month follow-up (p<0.001). The GFAP expression was significantly higher in dERMs (p = 0.001).

Conclusion

The intraretinal changes are different in iERMs and dERMs, as increased expression of CEIFLs in iERMs vs ICs in dERMs. The CEIFLs are associated with worse anatomical and functional outcomes in iERMs, whereas GFAP espression in peeled ILMs is higher in dERMs.

N-Formyl Peptide Receptors Induce Radical Oxygen Production in Fibroblasts Derived From Systemic Sclerosis by Interacting With a Cleaved Form of Urokinase Receptor

Systemic sclerosis (SSc) is a chronic autoimmune disease characterized by fibrosis, alteration in the microvasculature and immunologic abnormalities. It has been hypothesized that an abnormal redox state could regulate the persistent fibrotic phenotype in SSc patients. N-Formyl peptide receptors (FPRs) are chemotactic receptors overexpressed in fibroblasts derived from SSc patients. In this study, we demonstrated that stimulation of FPRs promotes the generation of reactive oxygen species (ROS) in skin fibroblasts. In fibroblast cells, ROS production was due to FPRs interaction with the urokinase receptor (uPAR) and to β₁ integrin engagement. FPRs cross-talk with uPAR and integrins led to Rac1 and ERKs activation. FPRs stimulation increased gp91phox and p67phox expression as well as the direct interaction between GTP-Rac1 and p67phox, thus promoting assembly and activation of the NADPH oxidase complex. FPRs functions occur through interaction with a specific domain of uPAR (residues ₈₈SRSRY₉₂) that can be exposed on the cell membrane by protease-mediated receptor cleavage. Immunohistochemistry analysis with a specific anti-SRSRY antibody showed increased expression of uPAR in a cleaved form, which exposes the SRSRY sequence at its N-terminus (DIIDIII-uPAR88–92) in skin biopsies from SSc patients. As expected by the increased expression of both FPRs and DII-DIII-uPAR_88-92, fibroblasts derived from SSc patients showed a significantly increase in ROS generation both at a basal level than after FPRs stimulation, as compared to fibroblasts from normal subjects. C37, a small molecule blocking the interaction between FPRs and uPAR, and selumetinib, a clinically approved MAPKK/ERK inhibitor, significantly inhibited FPRs-mediated ROS production in fibroblasts derived from SSc patients. Thus, FPRs, through the interaction with the uPA/uPAR system, can induce ROS generation in fibroblasts by activating the NADPH oxidase, playing a role in the alteration of the redox state observed in SSc.

Overexpression of chromatin assembly factor-1/p60 predicts biological behaviour of laryngeal carcinomas

This study analysed the immunohistochemical expression of the CAF-1/p60 protein in laryngeal cancers. CAF-1/p60 assumes an independent discriminative and prognostic value in laryngeal neoplasms; the presence of this protein in carcinoma in situ compared with laryngeal precancerous and larynx infiltrating tumours. We assessed the immunohistochemical expression of CAF-1/p60 in 30 cases of moderate and/or severe dysplasia, 30 cases of carcinoma in situ and 30 cases of laryngeal squamous cell carcinoma (LSCCs). CAF-1/p60 expression increased significantly according to the high index of neoplastic cellular replication; therefore, CAF-1/p60 was overexpressed in neoplastic cells and its moderate-severe expression is correlated with poorer prognosis compared to less expression. In conclusion, overexpression of the CAF-1/p60 protein is related to a risk of higher morbidity and mortality and is a reliable independent prognostic index of laryngeal carcinoma. CAF1-p60 protein overexpression can be used in cancer management as an indicator of malignant evolution, especially in carcinoma in situ.

The combined effect of USP7 inhibitors and PARP inhibitors in hormone-sensitive and castration-resistant prostate cancer cells

Purpose of the study

Reduced levels of the tumor suppressor protein CCDC6 sensitize cancer cells to the treatment with PARP-inhibitors. The turnover of CCDC6 protein is regulated by the de-ubiquitinase USP7, which also controls the androgen receptor (AR) stability. Here, we correlated the expression levels of CCDC6 and USP7 proteins in primary prostate cancers (PC). Moreover, we tested the efficacy of the USP7 inhibitors, in combination with PARP-inhibitors as a novel therapeutic option in advanced prostate cancer.

Experimental techniques

PC cells were exposed to USP7 inhibitor, P5091, together with cycloheximide, to investigate the turnover of the USP7 substrates, AR and CCDC6. As outcome of the AR downregulation, transcription targets of AR and its variant V7 were examined by qPCR. As a result of CCDC6 degradation, the induction of PARP inhibitors sensitivity was evaluated by analyzing PC cells viability and foci formation. We scored and correlated CCDC6 and USP7 expression levels in a prostate cancer tissue microarray (TMA).

Results

P5091 accelerated the degradation of AR and V7 isoform affecting PSA, UBE2C, CDC20 transcription and PC cells proliferation. Moreover, P5091 accelerated the degradation of CCDC6 sensitizing the cells to PARP-inhibitors, that acted sinergistically with genotoxic agents. The immunohistochemical analysis of both CCDC6 and USP7 proteins exhibited significant correlation for the intensity of staining (p ≤ 0.05).

Data interpretation

Thus, CCDC6 and USP7 represent predictive markers for the combined treatment of the USP7-inhibitors and PARP-inhibitors in advanced prostate cancer.

HPV Virus Transcriptional Status Assessment in a Case of Sinonasal Carcinoma

Human Papilloma Virus (HPV) can play a causative role in the development of sinonasal tract malignancies. In fact, HPV may be the most significant causative agent implicated in sinonasal tumorigenesis and is implicated in as many as 21% of sinonasal carcinomas. To date, there are no definitive, reliable and cost-effective, diagnostic tests approved by the FDA for the unequivocal determination of HPV status in head and neck cancers. We followed an exhaustive algorithm to correctly test HPV infection, including a sequential approach with p16INK4a IHC, viral DNA genotyping and in situ hybridization for E6/E7 mRNA. Here, we report a case of sinonasal carcinoma with discordant results using HPV test assays. The tumor we describe showed an irregular immunoreactivity for p16INK4a, and it tested positive for HPV DNA; nevertheless, it was negative for HR-HPV mRNA. We discuss the possible meaning of this discrepancy. It would be advisable to test HPV transcriptional status of sinonasal carcinoma on a diagnostic routine basis, not only by p16INK4a IHC assay, but also by HPV DNA genotyping and HR-HPV mRNA assessment.

MAPK15 upregulation promotes cell proliferation and prevents DNA damage in male germ cell tumors

Germ cell tumors (GCT) are the most common malignancies in males between 15 and 35 years of age. Despite the high cure rate, achieved through chemotherapy and/or surgery, the molecular basis of GCT etiology is still largely obscure. Here, we show a positive correlation between MAPK15 (ERK8; ERK7) expression and specific GCT subtypes, with the highest levels found in the aggressive embryonal carcinomas (EC). Indeed, in corresponding cellular models for EC, MAPK15 enhanced tumorigenicity in vivo and promoted cell proliferation in vitro, supporting a role for this kinase in human GCT. At molecular level, we demonstrated that endogenous MAPK15 is necessary to sustain cell cycle progression of EC cells, by limiting p53 activation and preventing the triggering of p53-dependent mechanisms resulting in cell cycle arrest.

To understand MAPK15-dependent mechanisms impinging on p53 activation, we demonstrate that this kinase efficiently protects cells from DNA damage. Moreover, we show that the ability of MAPK15 to control the autophagic process is necessary for basal management of DNA damage and for tumor formation controlled by the kinase.

In conclusion, our findings suggest that MAPK15 overexpression may contribute to the malignant transformation of germ cells by controlling a “stress support” autophagic pathway, able to prevent DNA damage and the consequent activation of the p53 tumor suppressor. Moreover, in light of these results, MAPK15-specific inhibitors might represent new tools to enhance the therapeutic index of cytotoxic therapy in GCT treatment, and to increase the sensitivity to DNA-damaging drugs in other chemotherapy-resistant human tumors.

Expression of FK506-binding protein 51 (FKBP51) in Mycosis fungoides

BACKGROUND

Mycosis fungoides (MF) is the major subtype of cutaneous T-cell lymphomas (CTCL). It usually has a prolonged indolent clinical course with a minority of cases acquiring a more aggressive biological profile and resistance to conventional therapies, partially attributed to the persistent activation of nuclear factor-kappa B (NF-κB) pathway. In the last decade, several papers suggested an important role for the FK506-binding protein 51 (FKBP51), an immunophilin initially cloned in lymphocytes, in the control of NF-κB pathway in different types of human malignancies.

OBJECTIVES

We aimed to investigate the possible value of FKBP51 expression as a new reliable marker of outcome in patients with MF.

METHODS

We assessed by immunohistochemistry (IHC) FKBP51 expression in 44 patients with MF, representative of different stages of the disease. Immunohistochemical results were subsequently confirmed at mRNA level with quantitative PCR (qPCR) in a subset of enrolled patients. In addition, IHC and qPCR served to study the expression of some NF-κB-target genes, including the tumour necrosis factor receptor-associated factor 2 (TRAF2).

RESULTS

Our results show that FKBP51 was expressed in all evaluated cases, with the highest level of expression characterizing MFs with the worst prognosis. Moreover, a significant correlation subsisted between FKBP51 and TRAF2 IHC expression scores.

CONCLUSIONS

We hypothesize a role for FKBP51 as a prognostic marker for MF and suggest an involvement of this immunophilin in deregulated NF-κB pathway of this CTCL.

Coexistent Squamous Cell Carcinoma and Granular Cell Tumor of Head and Neck Region: Report of Two Very Rare Cases and Review of the Literature

Granular cell tumor (GCT), a relatively rare neuroectodermal tumor occurring most often in the head and neck region, is not uncommonly associated with pseudoepitheliomatous hyperplasia of the overlying surface epithelium, which may be at times nonreadily distinguishable from well-differentiated squamous cell carcinoma (SCC). To the best of our knowledge, only a handful of coexisting SCC and GCT, mostly described in the esophagus, have been reported in (the current) literature so far. We herein report 2 new cases of coexisting GCT and SCC of the head and neck region, located, respectively, in larynx and tongue; comment on their clinical, imaging, and pathologic features; and discuss their management. In the present work, we also review the literature concerning this association to contribute to the head and neck pathologists' and surgeons' awareness regarding the possibility of this association for an adequate surgical excision and a better management of these patients.

A regulatory role for the co-chaperone FKBP51s in PD-L1 expression in glioma

Background

FKBP51 is a co-chaperone with isomerase activity, abundantly expressed in glioma. We previously identified a spliced isoform (FKBP51s) and highlighted a role for this protein in the upregulation of Programmed Death Ligand 1 (PD-L1) expression in melanoma. Because gliomas can express PD-L1 causing a defective host anti-tumoral immunity, we investigated whether FKBP51s was expressed in glioma and played a role in PD-L1 regulation in this tumour.

Methods

We used D54 and U251 glioblastoma cell lines that constitutively expressed PD-L1. FKBP51s was measured by immunoblot, flow cytometry and microscopy. In patient tumours, IHC and qPCR were used to measure protein and mRNA levels respectively. FKBP51s depletion was achieved by siRNAs, and its enzymatic function was inhibited using selective inhibitors (SAFit). We investigated protein maturation using N-glycosidase and cell fractionation approaches.

Results

FKBP51s was expressed at high levels in glioma cells. Glycosylated-PD-L1 was increased and reduced by FKBP51s overexpression or silencing, respectively. Naïve PD-L1 was found in the endoplasmic reticulum (ER) of glioma cells complexed with FKBP51s, whereas the glycosylated form was measured in the Golgi apparatus. SAFit reduced PD-L1 levels (constitutively expressed and ionizing radiation-induced). SAFit reduced cell death of PBMC co-cultured with glioma.

Conclusions

Here we addressed the mechanism of post-translational regulation of PD-L1 protein in glioma. FKBP51s upregulated PD-L1 expression on the plasma membrane by catalysing the protein folding required for subsequent glycosylation. Inhibition of FKBP51s isomerase activity by SAFit decreased PD-L1 levels. These findings suggest that FKBP51s is a potential target of immunomodulatory strategies for glioblastoma treatment.

Abstract 586: Ionizing radiation-induced PD-L1 upregulation in glioma: a crucial role for the molecular chaperone FKBP5

Glioblastoma can avoid immune surveillance and induce tumor tolerance, through inhibitory molecules, e.g. PD-L1. Ionizing radiation (IR), used to treat this tumor, is known to increase tumor expression of PD-L1, thus inducing resistance mechanisms. Finding molecular determinants involved in IR-induced PD-L1 may provide a target for preventing such an effect and improve radiotherapy outcomes. We demonstrated that the short isoform of the cochaperone FKBP51 (FKBP51s) regulated PD-L1 expression in melanoma. In glioma, FKBP51s was expressed at high levels, together with PD-L1 and its silencing reduced PD-L1 levels. Conversely, overexpression of FKBP51s increased PD-L1. Different PD-L1 isoforms were observed by immunoblot. A lower band (~37 kDa) corresponding to the naïve protein and two upper bands (~50, ~68 kDa) ascribable to post-translationally modified isoforms. FKBP51s was found mainly bound to the heaviest bands of PD-L1, reasonably mature protein, while the canonical isoform FKBP51 appeared to bind only the naïve protein. Mature PD-L1 protein consists in carbohydrates addition, the principal chemical modification to most plasma membrane proteins, and, particularly, N-glycosylation. Treatment of immunoprecipitated PD-L1 protein with PNGaseF produced a decrease of the highest band and the appearance of a lower band, corresponding to the naïve PD-L1, in accordance with the concept that the heaviest band of PD-L1 is a glycosylated form. Moreover, following subcellular fractionation to obtain extracts from ER and Golgi compartments, we found that naïve 37 kDa PD-L1 was detectable in the ER, but not in the Golgi. The PD-L1 glycosylated band was expressed in ER in a small proportion and mostly in the Golgi. FKBP51s, but not the canonical FKBP51, was found in ER. Co-IP of FKBP51s and PD-L1 from ER extract confirmed the two proteins interacted each other in ER. Our results show that naïve PD-L1 colocalized in the ER of glioma cell complexed with FKBP51s, while the PD-L1 glycosylated form was measured in the Golgi apparatus. Treatment of glioma cell with increasing doses of IR upregulated PD-L1 expression, in a dose-response manner. Particularly, we found a significant increase in PD-L1 expression at 4 and 8 Gy, in comparison with unirradiated glioma cell. Moreover, IR induction of mature PD-L1 was efficiently counteracted by FKBP51s silencing. Subcellular fractionation of glioma cell subjected to IR in kinetics showed an early and transitory decrease in FKBP51s ER levels at 3hrs, in line with a reduction of the glycosylated band in the whole lysate. After 8 hrs from IR, FKBP51s rose up again in the ER inducing a full maturation of PD-L1. These findings suggested that FKBP51s has a role in catalyzing PD-L1 folding, an essential step to glycosylation, through which it controls the affinity for PD1. This study identifies FKBP51s as an essential element that regulates PD-L1 expression on glioma cell, which is exploited by the tumor to resist to IR.

Citation Format: Paolo D'Arrigo, Michele Russo, Elia Guadagno, Roberto Pacelli, Maria Laura Del Basso De caro, Anna Rea, Martina Tufano, Stefania Staibano, Gennaro Ilardi, Maria Fiammetta Romano, Simona Romano. Ionizing radiation-induced PD-L1 upregulation in glioma: a crucial role for the molecular chaperone FKBP5 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 586. doi:10.1158/1538-7445.AM2017-586

Confocal microscopy and imaging profilometry: A new tool aimed to evaluate aesthetic procedures

According to the American Academy of Aesthetic Plastic Surgeons, more than 11 million cosmetic surgical and nonsurgical procedures were performed by board-certified plastic surgeons, dermatologists and otolaryngologists in the United States, totaling more than 12 billion dollars. We performed a retrospective observational multi-centric study on patients treated with a non-animal origin cross-linked hyaluronic acid with different molecular weights for nasolabial folds, evaluating through a new imaging system, profilometric techniques with the confocal microscopy, the durability, the efficacy and the safety of this product. From 25 patients, 150 silicone casts were obtained: 75 casts of the right nasolabial fold and 75 casts of the left nasolabial fold. Roughness arithmetical average of the right fold at T2 decreased by 50% versus T0 and by 40% compared to T1; at T2, it decreased by the 45% versus T0 and by 35% compared to T1. No side effects were reported. Results proved that the analysis of the skin microreliefs through confocal microscopy is a new imaging system that allows to evaluate with precision and safety the results of aesthetic treatments such as fillers objectively.

Our experience in the treatment of Malignant Fibrous Hystiocytoma of the larynx: clinical diagnosis, therapeutic approach and review of literature

Hereditary spherocytosis (HS) and Chronic myelocytic leukemia (CML) are both life threatening hemotologic diseases. They are rarely seen to occur simultaneously in one individual patient. Here we demonstrate a case of HS associated with CML in this study. The patient is a young female, diagnosed with HS in 2005, and was given partial embolization of the splenic artery. She got significant remission after the procedure. In 2008, she was found abnormal in blood routine test, after bone marrow routine, chromosome and fusion gene tests, she was diagnosed with CML (chronic phase). She did not receive regular treatment until 3 months prior, and is currently being treated with Dasatimib. She achieved hematological remission, but had no significant improvement in chromosome and fusion gene figures. Due to her severe condition of hemolysis, a splenectomy or an allogeneic hematopoietic stem cell transplantation is considered.

USP7 inhibitors, downregulating CCDC6, sensitize lung neuroendocrine cancer cells to PARP-inhibitor drugs

OBJECTIVES

CCDC6 gene product is a tumor-suppressor pro-apoptotic protein, substrate of ATM, involved in DNA damage response and repair. Altered levels of CCDC6 expression are dependent on post-translational modifications, being the de-ubiquitinating enzyme USP7 responsible of the fine tuning of the CCDC6 stability. Thus, our aim was to investigate CCDC6 and USP7 expression levels in Lung-Neuroendocrine Tumors (L-NETs) to verify if they correlate and may be exploited as novel predictive therapeutic markers.

MATERIALS AND METHODS

Tumor tissues from 29 L-NET patients were investigated on tissue microarrays. CCDC6 levels were scored and correlated with immunoreactivity for USP7. Next generation sequencing (NGS) of a homogenous group of Large Cell Neuroendocrine Carcinoma (LCNEC) (N=8) was performed by Ion AmpliSeq NGS platform and the Ion AmpliSeq Cancer Hotspot Panel v2. The inhibition of USP7, using P5091, was assayed in vitro to accelerate CCDC6 turnover in order to sensitize the neuroendocrine cancer cells to PARP-inhibitors, alone or in association with cisplatinum.

RESULTS

The immunostaining of 29 primary L-NETs showed that the intensity of CCDC6 staining correlated with the levels of USP7 expression (p≤0.05). The NGS analysis of 8 LCNEC revealed mutations in the hot spot regions of the p53 gene (in 6 out of 8). Moreover, gene polymorphisms were identified in the druggable STK11, MET and ALK genes. High intensity of p53 immunostaining was reported in the 6 tissues carrying the TP53 mutations. The inhibition of USP7 by P5091 accelerated the degradation of CCDC6 versus control in cycloheximide treated L-NET cells in vitro and sensitized the cells to PARP-inhibitors alone and in combination with cisplatinum.

CONCLUSION

Our data suggest that CCDC6 and USP7 have a predictive value for the clinical usage of USP7 inhibitors in combination with the PARP-inhibitors in L-NET in addition to standard therapy.

TLR4 down-regulation identifies high risk HPV infection and integration in head and neck squamous cell carcinomas

TLRs are main actors of the innate immune response against HPV. There are very few studies on the role of TLRs mediated HPV clearance in Head and Neck oncology. Our aim was to evaluate whether TLR4 expression identifies HPV infection and/or HR-HPV integration status in oral and oropharyngeal cancers. By immunohistochemistry we assessed TLR4 levels in OSCC/OPSCC. To detect viral integration or episomic status In situ hybridization for HPV-DNA and Pyro-sequencing techniques have been performed. The relationship between TLR4 expression with HPV infection status has been investigated. ISH HPV positive samples have reported lower levels of TLR4 intensity than negative samples (p = .002). There was no statistical correlation between TLR4 intensity and PCR HPV results (p more than 0.0.5). Point-biserial correlation coefficient revealed significant association between TLR4 expression and HR-HPV integration status (p = .0001) and between TLR4 expression index and HR-HPV infection (p = .001). These data have shown that TLR4 down-regulation is strongly associated to both HPV-16 infection and its integration into the host DNA.

A rare case of coexistence of metastasis from head and neck squamous cell carcinoma and tuberculosis within a neck lymph node

Coexistence of metastasis from squamous cell carcinoma and tuberculosis within lymph nodes is rare. We report a case of 86 years old woman with a mass in the left laterocervical region. The patient had undergone excision of a poorly differentiated squamous cell carcinoma from the mucosa of the left cheek, a few months before. Histological examination of a mass of few fused lymph nodes, isolated from left laterocervical lymphadenectomy, showed metastatic squamous cell carcinoma with concomitant granulomatous inflammation. A diagnosis of tuberculosis associated with malignancy was posed. The suspect was confirmed by a positive anamnestic finding of a previous tuberculosis infection. The granulomatous reaction may be associated with many types of tumor, and can be found in the draining lymph nodes. The possibility that this reaction is also due to a tuberculosis infection should be kept in mind for elderly oncology patient.

Immunomodulatory pathways regulate expression of a spliced FKBP51 isoform in lymphocytes of melanoma patients

FKBP51 (gene FKBP5) is an immunophilin capable of immunosuppression expressed in melanoma and lymphocytes. We found increased levels of a spliced FKBP5 variant in the PBMCs of 124 patients with melanoma. This variant encodes for an unknown isoform (FKBP51s). We hypothesized that FKBP51s resulted from tumour interaction with immune cells, through PDL-1/PD-1. To address this issue, we performed melanoma/PBMC cocultures. Furthermore, the immunohistochemistry of 76 melanoma specimens served to investigate whether FKBP51s stained tumour infiltrating lymphocytes. Our results showed that PBMCs expressed FKBP51s when cocultured with melanoma. Tumour PDL-1 knockdown or anti-PD-1 reduced FKBP51s expression in cocultured PBMCs. IHC showed a strong FKBP51s signal in tumour infiltrating lymphocytes, and lymphocytes of the invasion front of the tumour, along with melanoma PDL-1 expression. When overexpressed in melanoma, FKBP51s facilitated PDL-1 expression on the cell surface. In conclusion, our study shows that FKBP51s marks the PBMCs of patients with melanoma and is exploited by the tumour to immunomodulate through PDL-1.

FTIR microspectroscopic characterization of Spitz nevi

In the last 10 years, few efforts have been carried out to apply vibrational spectroscopy in the study of dermal pathologies in order to characterize the most relevant spectral markers for distinguishing benign from cancerous lesions. Spitz nevi are a special group of benign melanocytic lesions, characterized by spindled and/or epithelioid nevomelanocytes, with peculiar clinical, dermoscopic and histopathological features. The "atypical forms" of Spitz nevi are among the commonest problems of differential diagnosis with the so-called "spitzoid melanomas". The clinical and histological criteria for discriminating these two entities are very subtle and often still quite subjective, and, in a significant percentage of cases, can lead to diagnostic pitfalls and inadequate therapies. Therefore, it is noteworthy to outline that the diagnosis of melanocytic lesions still represents a challenging problem and a continue matter of discussion. We exploited FTIR microspectroscopy to study the different kinds of spitzoid melanocytes, in order to define the most relevant spectral markers of each specimen and to achieve objective information on "borderline" histologically atypical lesions. In particular, the spectroscopic investigation was carried out on melanocytes deriving from normal skin (as a normal control), malignant melanoma and Spitz nevi. The presence of the characteristic bands of melanin was investigated, too.

Confocal laser endomicroscopy in breast surgery: a pilot study

Background

Breast neoplasms include different histopathological entities, varying from benign tumors to highly aggressive cancers. Despite the key role of imaging, traditional histology is still required for a definitive diagnosis. Confocal Laser Endomicroscopy (CLE) is a new technique, which enables to obtain histopathological images in vivo, currently used in the diagnosis of gastrointestinal diseases. This is a single-center pilot feasibility study; the main aim is to describe the basic morphological patterns of Confocal Laser Endomicroscopy in normal breast tissue besides benign and malignant lesions.

Methods

Thirteen female patients (mean age 52.7, range from 22 to 86) who underwent surgical resection for a palpable breast nodule were enrolled. CLE was performed soon after resection with the Cellvizio® Endomicroscopy System (Mauna Kea Technologies, Paris, France), by using a Coloflex UHD-type probe; intravenous fluorescein was used as contrast-enhancing agent. The surgical specimen was cut along the main axis; dynamic images were obtained and recorded using a hand-held probe directly applied both to the internal part of the lesion and to several areas of surrounding normal tissue. Each specimen was then sent for definitive histologic examination.

Results

Histopathology revealed a benign lesion in six patients (46%), while a breast cancer was diagnosed in seven women (54%). Confocal laser endomicroscopy showed some peculiar morphological patterns. Normal breast tissue was characterized by a honeycomb appearance with regular, dark, round or hexagonal glandular lobules on a bright stroma background; tubular structures, representing ducts or blood vessels, were also visible in some frames. Benign lesions were characterized by a well-demarcated “slit-like” structure or by lobular structures in abundant bright stroma. Finally, breast cancer was characterized by a complete architectural subversion: ductal carcinoma was characterized by ill-defined structures, with dark borders and irregular ductal shape, formingribbons, tubules or nests; mucinous carcinoma showed smaller cells organized in clusters, floating in an amorphous extracellular matrix.

Conclusions

This is the first pilot study to investigate the potential role of confocal laser imaging as a diagnostic tool in breast diseases. Further studies are required to validate these results and establish the clinical impact of this technique.

Anal Melanoma With Neuroendocrine Differentiation

Melanoma of the anal cavity is an uncommon malignant tumor with an aggressive clinical behavior. The presence of nonmelanocytic cell or tissue components, designated as divergent differentiation, is an unusual but well-documented phenomenon in melanoma. We experienced a rare case of amelanotic melanoma with neuroendocrine differentiation of the anal canal, occurring in a 68-year old woman. This tumor was characterized by a clear-cut radial growth phase and an invasive component composed of a diffuse small cells population positive for neuroendocrine markers with a focal but convincing co-expression of S100 protein. To the best of our knowledge, this represents the first case of neuroendocrine differentiation in a primary melanoma of the anal cavity. Although anal melanoma with neuroendocrine differentiation is exceptional, clinical practitioners should be aware of its possibility at this site.

Histopathological determinants of tumor resistance: a special look to the immunohistochemical expression of carbonic anhydrase IX in human cancers

Intrinsic and acquired drug resistance of tumor cells still causes the failure of treatment regimens in advanced human cancers. It may be driven by intrinsic tumor cells features, or may also arise from micro environmental influences. Hypoxia is a microenvironment feature associated with the aggressiveness and metastasizing ability of human solid cancers. Hypoxic cancer cells overexpress Carbonic Anhydrase IX (CA IX). CA IX ensures a favorable tumor intracellular pH, while contributing to stromal acidosis, which facilitates tumor invasion and metastasis. The overexpression of CA IX is considered an epiphenomenon of the presence of hypoxic, aggressive tumor cells. Recently, a relationship between CA IX overexpression and the cancer stem cells (CSCs) population has been hypothesized. CSCs are strictly regulated by tumor hypoxia and drive a major non-mutational mechanism of cancer drug-resistance. We reviewed the current data concerning the role of CA IX overexpression in human malignancies, extending such information to the expression of the stem cells markers CD44 and nestin in solid cancers, to explore their relationship with the biological behavior of tumors. CA IX is heavily expressed in advanced tumors. A positive trend of correlation between CA IX overexpression, tumor stage/grade and poor outcome emerged. Moreover, stromal CA IX expression was associated with adverse events occurrence, maybe signaling the direct action of CA IX in directing the mesenchymal changes that favor tumor invasion; in addition, membranous/cytoplasmic co-overexpression of CA IX and stem cells markers were found in several aggressive tumors. This suggests that CA IX targeting could indirectly deplete CSCs and counteract resistance of solid cancers in the clinical setting.

New therapeutic perspectives in CCDC6 deficient lung cancer cells

Non-small cell lung cancer (NSCLC) is the main cause of cancer-related death worldwide and new therapeutic strategies are urgently needed. In this study, we have characterized a panel of NSC lung cancer cell lines for the expression of coiled-coil-domain containing 6 (CCDC6), a tumor suppressor gene involved in apoptosis and DNA damage response. We show that low CCDC6 protein levels are associated with a weak response to DNA damage and a low number of Rad51 positive foci. Moreover, CCDC6 deficient lung cancer cells show defects in DNA repair via homologous recombination. In accordance with its role in the DNA damage response, CCDC6 attenuation confers resistance to cisplatinum, the current treatment of choice for NSCLC, but sensitizes the cells to olaparib, a small molecule inhibitor of the repair enzymes PARP1/2. Remarkably, the combination of the two drugs is more effective than each agent individually, as demonstrated by a combination index <1. Finally, CCDC6 is expressed at low levels in about 30% of the NSCL tumors we analyzed by TMA immunostaining. The weak CCDC6 protein staining is significatively correlated with the presence of lymph node metastasis (p ≤ 0.02) and negatively correlated to the disease free survival (p ≤ 0.01) and the overall survival (p ≤ 0.05). Collectively, the data indicate that CCDC6 levels provide valuable insight for OS. CCDC6 could represent a predictive biomarker of resistance to conventional single mode therapy and yield insight on tumor sensitivity to PARP inhibitors in NSCLC.

Critical role of CCDC6 in the neoplastic growth of testicular germ cell tumors

Background

DNA damage response has been clearly described as an anti-cancer barrier in early human tumorigenesis. Moreover, interestingly, testicular germ cell tumors (TGCTs) have been reported to lack the DNA Damage Response (DDR) pathway activation.

CCDC6 is a pro-apoptotic phosphoprotein substrate of the kinase ataxia telangectasia mutated (ATM) able to sustain DNA damage checkpoint in response to genotoxic stress and is commonly rearranged in malignancies upon fusion with different partners.

In our study we sought to determine whether CCDC6 could have a role in the patho-genesis of testicular germ cell tumors.

Methods

To achieve this aim, analysis for CCDC6 expression has been evaluated on serial sections of the mouse testis by immunohistochemistry and on separate populations of murine testicular cells by western blot. Next, the resistance to DNA damage-induced apoptosis and the production of reactive oxygen species has been investigated in GC1 cells, derived from immortalized type B murine germ cells, following CCDC6 silencing. Finally, the CCDC6 expression in normal human testicular cells, in Intratubular Germ Cell Neoplasia Unclassified (IGCNU), in a large series of male germ cell tumours and in the unique human seminoma TCam2 cell line has been evaluated by immunohistochemistry and by Western Blot analyses.

Results

The analysis of the CCDC6 expression revealed its presence in Sertoli cells and in spermatogonial cells. CCDC6 loss was the most consistent feature among the primary tumours and TCam2 cells. Interestingly, following treatment with low doses of H₂O₂, the silencing of CCDC6 in GC1 cells caused a decrease in the oxidized form of cytochrome c and low detection of Bad, PARP-1 and Caspase 3 proteins. Moreover, in the silenced cells, upon oxidative damage, the cell viability was protected, the γH2AX activation was impaired and the Reactive Oxygen Species (ROS) release was decreased.

Conclusions

Therefore, our results suggest that the loss of CCDC6 could aid the spermatogonial cells to be part of a pro-survival pathway that helps to evade the toxic effects of endogenous oxidants and contributes to testicular neoplastic growth.

Synergy between enzastaurin doxorubicin in inducing melanoma apoptosis

Melanoma is resistant to most standard chemotherapeutics. We analysed the combined effect of doxorubicin and enzastaurin on cell death of four melanoma cell lines, namely G361, SK-MEL3, A375 and SAN. Enzastaurin IC50 was calculated by measure of growth inhibition with MTS assay and corresponded to 2 μM; the half maximal cytotoxicity of doxorubicin was obtained at 3 μM dose. Evaluation of combination index showed synergism (CI > 1) or additive effect (CI = 1) with all melanoma cell lines, with enzastaurin doses ≥0.6 μM and doxorubicin doses ≥1 μM. Combination of the two drugs resulted in increase in caspase 3 and 8 activation, in comparison with activation by single agents. Caspase 8 activation was impaired by TNFR-1 blocking. Our results show doxorubicin-stimulated production of TNFα, whereas enzastaurin-stimulated TNFR-1 expression on plasma membrane. The effect on TNFR-1 appeared to be mediated by PKCζ inhibition. Taken together, our findings suggest that enzastaurin increases doxorubicin-induced apoptosis of melanoma by a mechanism involving, at least in part, activation of the TNF-α signal.

Clinical, dermoscopic and histological features of a Merkel cell carcinoma of the hand

BACKGROUND

Merkel cell carcinoma (MCC) is a rare and typically aggressive form of skin cancer. The benign appearance of the tumor usually on exposed skin parts, contrasting with its extensive microscopic invasion, can delay timely diagnosis.

MAIN OBSERVATIONS

We report a case of a 71-year-old man with a slowly progressive nodule on the left hand.

CONCLUSION

At the dermoscopic examination, the presence of a polymorphous vascular pattern, including milky-red areas may constitute an additional clinical clue to accurately diagnose this rare tumor. Clinical, dermoscopic and histological features are discussed.

Tissue microarray-based evaluation of Chromatin Assembly Factor-1 (CAF-1)/p60 as tumour prognostic marker

In this study we aimed to confirm the emerging role of Chromatin Assembly Factor 1 (CAF-1 p60) as a new proliferation and prognostic marker for cancer and to test the usefulness of the tissue microarray technique (TMA) for CAF-1 p60 rapid screening in several human malignancies. CAF-1 is a histone chaperone, regulating chromatin dynamics during DNA replication and repair in eukaryotics. TMA is a powerful high-throughput methodology in the study of cancer, allowing simultaneous assessment of different biomarkers within large numbers of tissue specimens. We generated TMA taking 3 mm diameter-core biopsies from oral squamous cell carcinoma, prostate cancer, salivary gland tumours and skin melanoma specimens, which had been previously tested for CAF-1 p60 on routine tissue sections. We also analysed, for the first time, 30 larynx and 30 skin squamous cell carcinomas. CAF-1 p60 resulted over-expressed in both the tissue sections and the TMA specimens, with the highest levels of expression in tumours which were more aggressive and metastasizing. Notably, a high degree of agreement was found between the CAF-1 p60 assessment on TMAs and on routine tissue sections. Our findings confirm the prognostic role of CAF-1 p60 and indicate TMA as a really advantageous method for CAF-1 p60 immunohistochemical screening, allowing savings on both tissue quantity and operator-time.

Overexpression of chromatin assembly factor-1 p60, poly(ADP-ribose) polymerase 1 and nestin predicts metastasizing behaviour of oral cancer

Aims

The natural history of oral squamous cell carcinomas (OSCCs) is variable and difficult to predict. This study aimed to assess the value of the expression of poly(ADP-ribose) polymerase 1 (PARP-1), chromatin assembly factor-1 (CAF-1)/p60 and the stem cell markers CD133, CD166, CD44, CD44v6 and nestin as markers of outcome and progression-free survival in OSCC patients.

Methods

Clinical data were collected from 66 patients (41 male and 25 female, aged 29–92 years) who underwent surgery for OSCC of the tongue, floor, lips, and palate. During follow-up (range: 12–131 months), 14 patients experienced relapse/metastasis and/or death. The study was performed by immunohistochemistry on paraffin-embedded tumour tissues, western blot analysis of tumour protein lysates and human cell lines, and RNA silencing assays. In addition, the human papillomavirus (HPV) status of primary tumours was evaluated by immunohistochemistry and viral subtyping. Univariate and multivariate analyses were performed to determine the correlation between these parameters and the clinical and pathological variables of the study population.

Results and conclusions

We found that a PARP-1^high/CAF-1 p60^high/nestin^high phenotype characterized the OSCCs with the worst prognosis (all HPV-negative). This may be of benefit in clinical management, since radio-enhancing anti-PARP-1 and/or anti-CAF-1/p60 agents may allow radioresistance to be bypassed in the nestin-overexpressing, metastasizing OSCC cells.

Abstract 5626: FKBP51 is a crucial modulator of melanoma plasticity and promising molecular target for preventing melanoma metastasis

FKBP51, a protein with a relevant role in developmental stages in mammals and other organisms, is highly expressed in melanoma and correlates with tumor aggressiveness and resistance to therapy. We found that FKBP51 positively regulates melanoma cancer stem cell (CSC) phenotype at the transcriptional level. We also found that melanoma CSCs are endowed with epithelial to mesenchimal transition (EMT) traits. The immunochemistry study of 10 primitive cutaneous and 20 brain melanoma metastases showed that melanocytic cells capable of extravasation and subverting the architecture of metastatic tissue display intense FKBP51 nuclear signal and cytoplasmic positivity for the CSC marker nestin. These findings support the conclusion that the genetic programs of cancer stemness and invasiveness overlap in melanoma, and that FKBP51 plays a pivotal role in sustaining such a program. To confirm the role of FKBP51 in melanoma invasion, we utilized an experimental metastasis model. Animal studies were performed in accordance with NIH recommendations and the approval of the local institutional animal research committee. Injecting SAN melanoma cells into the tail vein of IL2γ-NOD-SCID mice produced prominent multifocal lesions in lungs and liver. We systemically administered two separate doses of FKBP51 siRNA to mice after the injection of melanoma cells. Organ colonization was evaluated both in live animals and post mortem. Qualitative PET/CT image analysis demonstrated low FDG uptake limited to small areas in lungs and liver. By contrast, untreated mice had diffuse metastatic liver and lung lesions and high FDG uptake in the same organs. Quantitative analysis performed on PET/CT images revealed that mean standardized uptake values (SUV) in treated mice were significantly lower than in untreated mice, both for lungs and liver. High Frequency Ultrasound examination revealed few or no liver metastases in treated mice versus untreated mice. Post-mortem organ examination showed a dramatic difference between the morphologically preserved organs dissected from treated mice, and severely compromised organs from untreated mice. The histological examination confirmed these findings. Most interestingly, invading cells co-expressed FKBP51 and nestin. Our study suggests a prominent role for FKBP51 in the pathogenesis of metastatic melanoma; we envision that targeting this protein for melanoma metastasis prevention may produce a successful outcome.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5626. doi:1538-7445.AM2012-5626

Epigenetic disregulation in oral cancer

Squamous cell carcinoma of the oral region (OSCC) is one of the most common and highly aggressive malignancies worldwide, despite the fact that significant results have been achieved during the last decades in its detection, prevention and treatment. Although many efforts have been made to define the molecular signatures that identify the clinical outcome of oral cancers, OSCC still lacks reliable prognostic molecular markers. Scientific evidence indicates that transition from normal epithelium to pre-malignancy, and finally to oral carcinoma, depends on the accumulation of genetic and epigenetic alterations in a multistep process. Unlike genetic alterations, epigenetic changes are heritable and potentially reversible. The most common examples of such changes are DNA methylation, histone modification, and small non-coding RNAs. Although several epigenetic changes have been currently linked to OSCC initiation and progression, they have been only partially characterized. Over the last decade, it has been demonstrated that especially aberrant DNA methylation plays a critical role in oral cancer. The major goal of the present paper is to review the recent literature about the epigenetic modifications contribution in early and later phases of OSCC malignant transformation; in particular we point out the current evidence of epigenetic marks as novel markers for early diagnosis and prognosis as well as potential therapeutic targets in oral cancer.

Animal type melanoma: an unusual case with aggressive histological features?

Animal-type melanoma (ATM) refers to a well-known but rare, heavily pigmented melanocytic tumor, considered a variant of malignant melanoma, the biological behavior and prognostic significance of which still remain to be completely established. We report a case characterized by proliferation of hyperpigmented epithelioid and spindle cells, focally ulcerating the epidermis. Tumor necrosis, perineural and vascular invasion, as well as a slightly high mitotic index, were also observed. Although there were several features indicating poor prognosis, the lesion was diagnosed as ATM and not as classical melanoma. This almost unique case could help us to confirm the excellent biological behavior of this "uncertain malignant potential tumor", suggesting a biological nature of ATM possibly different from classical melanoma, as reported in other molecular studies. In addition, the first rapid impression of aggressive melanoma could lead the pathologist to render an immediate, incorrect diagnosis.