Expression of TP53, BCL-2, and VEGFA Genes in Esophagus Carcinoma and its Biological Significance

A Mendelian analysis of the causality between inflammatory cytokines and digestive tract cancers

PURPOSE

In this study, we performed a two-sample Mendelian randomization (MR) analysis to assess the causality between inflammatory cytokines and the risk of digestive tract cancers (DTCs). Furthermore, we conducted a molecular docking study to predict the therapeutic mechanisms of traditional Chinese medicine (TCM) compounds in the treatment of DTCs.

METHODS

In our MR analysis, genetic variations associated with eight types of DTCs were utilized, which were sourced from a large publicly available genome-wide association study dataset (7929 cases and 1 742 407 controls of European ancestry) and inflammatory cytokines data from a genome-wide association study summary of 8293 European participants. Inverse-variance weighted method, MR-Egger, and weighted median were performed to analyze and strengthen the final results. We investigated the effects of 41 inflammatory molecules on 8 types of DTCs. Subsequently, the effect of DTCs on positive inflammatory factors was analyzed by means of inverse MR. Molecular docking was exploited to predict therapeutic targets with TCM compounds.

RESULTS

Interleukin-7, interleukin-16, macrophage colony-stimulating factor, monokine induced by interferon-gamma, and vascular endothelial growth factor may be significantly associated with various types of DTCs. Five TCM compounds (baicalin, berberine, curcumin, emodin, and salidroside) demonstrated better binding energies to both interleukin-7 and vascular endothelial growth factor than carboplatin.

CONCLUSION

This study provides strong evidence to support the potential causality of some inflammatory cytokines on DTCs and indicates the potential molecular mechanism of TCM compounds in the treatment of DTCs. Key message What is already known on this topic  The increasing evidence indicates that inflammatory cytokines are implicated in the pathogenesis of digestive tract cancers (DTCs). Nevertheless, the causal relationship between inflammatory cytokines and DTCs remains indistinct. Additionally, certain traditional Chinese medicine compounds have been demonstrated to treat DTCs by influencing inflammatory factors, yet their underlying potential mechanisms remain ambiguous. What this study adds  In this study, Mendelian randomization analysis was performed for the first time regarding the causality between human inflammatory cytokines and eight types of DTCs, which revealed that inflammatory factors may play different roles in different types of DTCs. Moreover, molecular docking of key inflammatory factors was implemented, indicating the targets for drug actions. How this study might affect research, practice, or policy  This research has the potential to reveal the causality between 41 inflammatory factors and 8 DTCs, offering novel perspectives for the prevention and management strategies of DTCs. Additionally, it indicates the targets for the actions of traditional Chinese medicine on the key inflammatory factors of these cancers.

Retracted: Expression of TP53, BCL-2, and VEGFA Genes in Esophagus Carcinoma and its Biological Significance

The Editors of Medical Science Monitor wish to inform you that the above manuscript has been retracted from publication due to concerns with the credibility and originality of the study, the manuscript content, and the Figure images. Reference: Wei Wei, Yanqin Wang, Xiaoming Yu, Lan Ye, Yuhua Jiang, Yufeng Cheng. Expression of TP53, BCL-2, and VEGFA Genes in Esophagus Carcinoma and its Biological Significance. Med Sci Monit, 2015; 21: 3016-3022. DOI: 10.12659/MSM.894640.

Sequence driven interaction of amino acids in de-novo designed peptides determines c-Myc G-quadruplex unfolding inducing apoptosis in cancer cells

c-MYC proto-oncogene harbors a putative G-quadruplex structure (Pu27) at the NHEIII₁ domain, which can shuffle between transcriptional inhibitor quadruplex and transcriptionally active duplex. In cancer cells this quadruplex destabilization is preferred and NHEIII₁ domain assume a duplex topology thereby inducing c-MYC overexpression and tumorigenesis. Hence, the c-MYC quadruplex acts as an excellent target for anti-cancer therapy. Though researcher have tried to develop G-quadruplex targeted small molecules, work with G-quadruplex targeting peptides is very limited. Here we present a peptide that can bind to c-MYC quadruplex, destabilize the tetrad core, and permit the formation of a substantially different structure from the quartet core seen in the canonical G-quadruplexes. Such conformation potentially acted as a roadblock for transcription factors thereby reducing cMYC expression. This event sensitizes the cancer cell to activate apoptotic cascade via the c-MYC-VEGF-A-BCL2 axis. This study provides a detailed insight into the peptide-quadruplex interface that encourages better pharmacophore design to target dynamic quadruplex structure. We believe that our results will contribute to the development, characterization, and optimization of G-quadruplex binding peptides for potential clinical application.

Downregulation of miR-375 contributes to ERBB2-mediated VEGFA overexpression in esophageal cancer

Esophageal cancer (EC) is a lethal cancer with an extremely aggressive nature and poor survival rate. However, the molecular mechanisms driving the occurrence and progression of EC are not well understood. MicroRNAs (miRNAs) are small RNA molecules that regulate the expression of protein-coding genes. miRNA-mediated gene regulation plays an important role in EC. By cross-referencing studies from NCBI, we found that microRNA-375 (miR-375) is one of the most frequently downregulated miRNAs in EC. We assessed expression of miR-375 in EC cell lines and primary EC tissues and their matched normal tissues. We found significant downregulation of miR-375 in both cell lines and EC tissues. Forced expression of miR-375 attenuated EC cell proliferation and invasion. Human epidermal growth factor receptor 2 (HER2, ERBB2), a known proto-oncogene, was identified here as one of the potential target genes of miR-375. Ectopic expression of miR-375 significantly suppressed the expression of ERBB2 and subsequently downregulated one of its target genes, vascular endothelial growth factor A (VEGFA), which is related to cancer invasion and metastasis. These findings suggest that miR-375 acts as a tumor suppressor by blocking the ERBB2/VEGFA pathway with the potential to modulate the occurrence and/ or progression of EC.

Correntropy-Based Hypergraph Regularized NMF for Clustering and Feature Selection on Multi-Cancer Integrated Data

Non-negative matrix factorization (NMF) has become one of the most powerful methods for clustering and feature selection. However, the performance of the traditional NMF method severely degrades when the data contain noises and outliers or the manifold structure of the data is not taken into account. In this article, a novel method called correntropy-based hypergraph regularized NMF (CHNMF) is proposed to solve the above problem. Specifically, we use the correntropy instead of the Euclidean norm in the loss term of CHNMF, which will improve the robustness of the algorithm. And the hypergraph regularization term is also applied to the objective function, which can explore the high-order geometric information in more sample points. Then, the half-quadratic (HQ) optimization technique is adopted to solve the complex optimization problem of CHNMF. Finally, extensive experimental results on multi-cancer integrated data indicate that the proposed CHNMF method is superior to other state-of-the-art methods for clustering and feature selection.

Inhomogeneity of stiffness and density of the extracellular matrix within the leukoplakia of human oral mucosa as potential physicochemical factors leading to carcinogenesis

Oral leukoplakia is a clinical term relating to various morphological lesions, including squamous cell hyperplasia, dysplasia and carcinoma. Leukoplakia morphologically manifested as hyperplasia with epithelial dysplasia is clinically treated as precancerous condition. Nevertheless, there is a lack of good markers indicating the transformation of premalignancies towards cancer. A better understanding of the mechanical environment within the tissues where tumors grow might be beneficial for the development of prevention, diagnostic, and treatment methods in cancer management. Atomic force microscopy (AFM) and immunohistology techniques were used to assess changes in the stiffness and morphology of oral mucosa and leukoplakia samples at different stages of their progression towards cancer. The Young's moduli of the tested leukoplakia samples were significantly higher than those of the surrounding mucus. Robust inhomogeneity of stiffness within leukoplakia samples, reflecting an increase in regeneration and collagen accumulation (increasing density) in the extracellular matrix (ECM), was observed. Within the histologically confirmed cancer samples, Young's moduli were significantly lower than those within the precancerous ones. Inhomogeneous stiffness within leukoplakia might act as "a mechanoagonist" that promotes oncogenesis. In contrast, cancer growth might require the reorganization of tissue structure to create a microenvironment with lower and homogenous stiffness. The immunohistology data collected here indicates that changes in tissue stiffness are achieved by increasing cell/ECM density. The recognition of new markers of premalignancy will aid in the development of new therapies and will expand the diagnostic methods.

Mechanism of autophagy regulating chemoresistance in esophageal cancer cells

The current study aimed to explore the mechanism of autophagy-regulating chemoresistance in esophageal cancer (EC) cells. Methods: 45 cases of esophageal cancer cell tissue and 25 cases of adjacent normal tissue excised in the surgical resection were collected from the tumor pathology department of our hospital from March to November 2017. The above cancer cells and paracancerous cells were cultured according to the cell culture procedures. The autophagy was induced by cisplatin in human esophageal cancer EC9706 cells line. The effect of autophagy on the survival of EC9706 cells was observed by autophagy inhibitor 3-MA. Cell viability was also measured by cell counting kit-8 (CCK-8). Apoptosis and cell cycle were detected by flow cytometry. Furthermore, monodansylcadaverine (MDC) was used to detect autophagy. Western blot was applied to determine the molecular changes during treatment. Diketopyrrolopyrrole (DPP) is able to inhibit cell proliferation, induce cell death and cell cycle arrest in the S phase. In addition, autophagy was activated through PI3K-III pathway. Results: 3-MA inhibitor plus 10% fetal bovine serum were added for culture, and the cell culture temperature and humidity were the best conditions. There were few autophagic vesicles in the stationary cells, where their brightness was weakened. There were more and brighter green fluorescent particles in the DPP group without a 3-MA inhibitor, indicating that autophagic parameters actually exist in this process. The apoptosis rate of DDP-induced cell death was not found to be the best, but was higher than that of the control group (P<0.05). The combination of DDP and 3-MA had a more obvious catalytic effect on apoptosis, and the apoptosis rate was much higher than that of single DDP (P<0.05), indicating that DDP was capable of inducing significant apoptosis after inhibiting autophagy. The combination of DDP and 3-MA had an obvious catalytic effect on apoptosis, and the apoptosis rate was higher than that of DDP alone (P < 0.05), suggesting that DDP could significantly improve the ability to induce apoptosis after inhibiting autophagy. The expression level of autophagy-related proteins was also detected by Western blotting. Our findings indicated that autophagy may be a self-protective mechanism of esophageal cancer cells induced by DDP, and its inhibition may be a new strategy for adjuvant chemotherapy in esophageal cancer.

ATP6V0D2, a subunit associated with proton transport, serves an oncogenic role in esophagus cancer and is correlated with epithelial-mesenchymal transition

BACKGROUND

The poor prognosis of esophagus cancer (EC) is mainly due to its high invasiveness and metastasis, so it is urgent to search effectively prognostic markers and explore their roles in the mechanism of metastasis.

MATERIALS AND METHODS

Based on the TCGA database, we downloaded the RNA-Seq for analyzing the expression of ATP6V0D2. QRT-PCR was used to test the mRNA levels of ATP6V0D2 in cell lines. Chi-square tests were used to evaluate the correlation between ATP6V0D2 and clinical characteristics. Prognostic values were determined by Kaplan-Meier methods and cox's regression models. CCK-8 and clone formation assays were employed to evaluate the cell viability, and Transwell assay was implemented to determine the invasive and migratory abilities. Correlations between ATP6V0D2 and motion-related markers were analyzed by the GEPIA database and confirmed by western blot. Moreover, the relationship between ATP6V0D2 and molecules related to cell cycle and apoptosis was also determined by western blot.

RESULTS

A significant increase was observed in 3 EC-related cell lines compared to the normal cell line. ATP6V0D2 has a connection with the poor prognosis and can be considered as an independent prognosticator for patients with EC. Besides, ATP6V0D2 can improve cells viability as well as invasive and migratory abilities. What's more, downregulation of ATP6V0D2 notably enhanced E-cadherin expression, while decreased N-cadherin, Vimentin, and MMP9 expression, whereas overexpression of ATP6V0D2 presented the opposite outcomes. Furthermore, we found that silencing ATP6V0D2 led to a significant reduction on the protein expression of Cyclin D1, CDK4, Bcl-2, whereas resulted in a notable enhancement on the Bax level.

CONCLUSION

ATP6V0D2 might be an independent prognosticator for EC patients, and it possibly promotes tumorigenesis by regulating epithelial-mesenchymal transition, cell cycle and apoptosis-related markers, providing the possibility that ATP6V0D2 may be a novel biomarker for the therapeutic intervention of EC.

Long intergenic non-coding RNA 00337 confers progression of esophageal cancer by mediating microrna-145-dependent fscn1

Long non-coding RNAs (lncRNAs) have been highlighted as prominent genetic modulators involved in multiple important biological processes of cancer cells, especially in esophageal cancer (EC). We tried to elucidate the potential role of LINC00337 in the progression of EC. Based on TCGA database analysis and Reverse transcription quantitative polymerase chain reaction determination, high expression of LINC00337 and FSCN1 was detected, while miR-145 exhibited a low expression in EC. LINC00337 was identified to bind to miR-145 to impair the miR-145-dependent FSCN1 inhibition. The underlying regulatory mechanisms were evaluated by transfection with LINC00337 overexpression plasmid, siRNA against LINC00337, miR-145 mimic, or anta-miR-145. Downregulation of LINC00337 results in increased Bax level, decreased FSCN1, Bcl-2, VEGF, and p53 levels, in addition to diminished cell proliferation, migration, invasion and tumor growth, with accelerated cell apoptosis by upregulating miR-145. Taken together, the findings obtained provided evidence suggesting that LINC00337 acts as a tumor promoter in EC, providing insight and advancements for EC treatment.

Downregulation of microRNA-224-3p Hampers Retinoblastoma Progression via Activation of the Hippo-YAP Signaling Pathway by Increasing LATS2

Purpose

The pivotal role of microRNAs (miRNAs or miRs) has been proved in the pathogenesis of retinoblastoma. miR-224-3p is demonstrated to be involved in several tumors. However, the underlying mechanism of miR-224-3p in retinoblastoma is yet to be investigated. Therefore, this study was designed to identify the regulation of miR-224-3p in human retinoblastoma.

Methods

The expression pattern of miR-224-3p and large tumor suppressor 2 (LATS2) in retinoblastoma was measured by reverse transcription quantitative polymerase chain reaction. Afterward, the interaction between miR-224-3p and LATS2 was identified using a dual luciferase reporter gene assay. Next, gain-of-function and loss-of-function approaches were employed to examine the effects of miR-224-3p and LATS2 as well as their interaction on cell apoptosis, proliferation and angiogenesis abilities, and tumorigenesis. Whether the Hippo-YAP signaling pathway was involved in tumorigenesis was analyzed by determining downstream genes.

Results

LATS2 was downregulated in retinoblastoma, and its overexpression promoted apoptosis and suppressed proliferation of retinoblastoma cells. miR-224-3p, highly expressed in retinoblastoma, inhibited the expression of its target gene LATS2, which inhibited activation of the Hippo-YAP signaling pathway. Suppression of miR-224-3p promoted apoptosis while suppressing the proliferation of retinoblastoma cells and angiogenesis. Tumor progression induced by upregulation of miR-224-3p was diminished by restoration of LATS2. It was observed that tumor growth and angiogenesis were reduced by depleted miR-224-3p in the animal experiments.

Conclusions

The present study suggests that miR-224-3p targets LATS2 and blocks the Hippo-YAP signaling pathway activation, thus preventing the progression of retinoblastoma, which could be a new therapeutic target for retinoblastoma.

Dysregulation of helper T lymphocytes in esophageal squamous cell carcinoma (ESCC) patients is highly associated with aberrant production of miR-21

Dysregulation of helper T (Th) cell subsets has been contributed to the initiation and propagation of esophageal squamous cell carcinoma (ESCC). Different microRNAs (miRNAs) have been reported to control the development and functions of tumor-associated immune cells in ESCC. Here, we aimed to assess the IL-10, TGF-β, IFN-γ, and IL-17a-producing CD3+CD8- T cells in association whit miR-21, miR-29b, miR-106a, and miR-155 expression in ESCC patients. A total of 34 ESCC patients including 12 newly diagnosed (ND) and 22 under-treatment (UT) cases and also 34 age-matched healthy donors were enrolled. Flow cytometric characterization of stimulated T cells was performed by staining of the cells with fluorescent conjugated specific anti-human CD3 and CD8 cell surface markers as well as IL-17a, IFN-γ, IL-10, and TGF-β intracytoplasmic cytokines. Circulating RNA was extracted from the plasma, and qRT-PCR was used to evaluate the expression of microRNAs. TGF-β plasma levels were also assessed by ELISA. Results showed that the frequency of Th cells was significantly reduced in patients. A significant increase in Treg as well as Th17 cells population in both patient subgroups was observed. ND patients showed elevated level of Th1 cells and IL-10. However the mean expression of IFN-γ was significantly decreased in Th cells. We also detected higher level of miR-21 in the ESCC patients which was significantly correlated with different subsets of Th cells. Our findings revealed that immune response related to the Th cells is highly impaired in ESCC patients. Association between miR-21 and Th subsets could be correlated with the impairment of anti-tumor immunity and ESCC pathogenesis, which could be potentially used as an important target for immunotherapeutic approaches.

Molecular and immune targets for Merkel cell carcinoma therapy and prevention

Merkel cell carcinoma (MCC) is a rare neuroendocrine carcinoma of the skin, for which the exact mechanisms of carcinogenesis remain unknown. Therapeutic options for this highly aggressive malignancy have historically been limited in both their initial response and response durability. Recent improvements in our understanding of MCC tumor biology have expanded therapeutic options for these patients, namely through the use of immunotherapies such as immune checkpoint inhibitors. Further elucidation of the tumor mutational landscape has identified molecular targets for therapies, which have demonstrated success in other cancer types. In this review, we discuss both current and investigational immune and molecular targets of therapy for MCC.

Non Melanoma Skin Cancer Pathogenesis Overview

(1) Background: Non-melanoma skin cancer is the most frequently diagnosed cancer in humans. The process of skin carcinogenesis is still not fully understood. However, several studies have been conducted to better explain the mechanisms that lead to malignancy; (2) Methods: We reviewed the more recent literature about the pathogenesis of non-melanoma skin cancer focusing on basal cell carcinomas, squamous cell carcinoma and actinic keratosis; (3) Results: Several papers reported genetic and molecular alterations leading to non-melanoma skin cancer. Plenty of risk factors are involved in non-melanoma skin cancer pathogenesis, including genetic and molecular alterations, immunosuppression, and ultraviolet radiation; (4) Conclusion: Although skin carcinogenesis is still not fully understood, several papers demonstrated that genetic and molecular alterations are involved in this process. In addition, plenty of non-melanoma skin cancer risk factors are now known, allowing for an effective prevention of non-melanoma skin cancer development. Compared to other papers on the same topic, our review focused on molecular and genetic factors and analyzed in detail several factors involved in non-melanoma skin cancer.

Expression of miR-711 and mechanism of proliferation and apoptosis in human gastric carcinoma

MicroRNAs (miRs) are involved in many aspects of cell biology, including cell proliferation and apoptosis, two critical aspects of tumor biology. We investigated the effect of miR-711 on Bcl-2 expression in human MGC803 gastric cancer cells and the mechanism of cell proliferation, apoptosis, and invasion. Expression of miR-711 and Bcl-2 was significantly increased in gastric adenocarcinoma compared to adjacent normal tissue. Inhibition of miR-711 in MGC803 gastric cancer cells decreased the expression of Bcl-2, decreased cell proliferation, decreased the invasion ability, and increased apoptosis. The expression of Bcl-2 protein correlated with clinical staging, lymph node metastasis, and tumor differentiation in patients with gastric cancer. The expression of miR-711 positively correlated with the expression of Bcl-2, suggesting that miR-711 and Bcl-2 are co-regulated and involved in the development of gastric cancer.

The transcription factor FOXA1 induces epithelial ovarian cancer tumorigenesis and progression

FOXA1 (forkhead box A1), a member of the FOXA transcription factor superfamily, plays an important role in tumor occurrence and development. However, the relationship between FOXA1 and ovarian cancer has not been reported. We examined normal ovarian tissue and ovarian cancer tissue and found increased FOXA1 expression in the cancer tissue. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and flow cytometry assays demonstrated that transfection with small interfering RNA to silence FOXA1 (si-FOXA1) in ovarian cancer cell lines decreased cell proliferation and induced apoptosis and S-phase arrest. In addition, si-FOXA1 transfection inhibited cell migration and invasion. Western blotting showed that si-FOXA1 transfection decreased the levels of YY1-associated protein 1, cyclin-dependent kinase 1, cyclin D1, phosphatidylinositol-3 kinase, E2F transcription factor 1, B-cell lymphoma 2, and vascular endothelial growth factor A protein. Based on these results, we suggest that FOXA1 plays a catalytic role in ovarian cancer pathogenesis and development by affecting the expression of the above-mentioned proteins.

Immunotherapy of Dual-Function Vector with Both Immunostimulatory and B-Cell Lymphoma 2 (Bcl-2)-Silencing Effects on Gastric Carcinoma

BACKGROUND Tumorigenesis is a kind of pathology marked by infinite proliferation and restrained apoptosis compared with normal cells. The abnormal expression of some proto-oncogenes and apoptosis inhibition are essential for tumor growth, which has been confirmed by molecular biologic and immunologic studies. The hypofunction of the host immune system also drives the development and metastasis of malignant tumors. Bcl-2, which has a critical role in regulating apoptosis, is overexpressed in several cancers. MATERIAL AND METHODS In this study, we constructed a dual-function small hairpin RNA (shRNA) vector containing an Bcl-2-silencing shRNA and a TLR7-stimulating ssRNA and examined it effect on tumor cell growth and proliferation. RESULTS Stimulation with this bi-functional vector in vitro promoted significant apoptosis of MFC cells by regulating the expression of apoptosis-related proteins and induced secretion of type I IFNs. Most importantly, this bi-functional vector more effectively inhibited subcutaneous MFC cell growth than did single shRNA and ssRNA treatment in vivo. Natural killer (NK) and CD4+ T cells were required for effective tumor suppression, and TLR7 was shown to play a helper role in the activation of NK cells and CD4+ T cells, possibly by regulating the expression of receptors or secretion of cytokines. CONCLUSIONS This bi-functional vector that contained ssRNA and shRNA may represent a promising approach for tumor therapy.

Association of VEGF Gene Polymorphisms with the Risk and Prognosis of Cutaneous Squamous Cell Carcinoma

BACKGROUND Cutaneous squamous cell carcinoma (cSCC) is the second most common type of non-melanoma skin cancer (NMSC) globally. The aims of this study were to further systematically clarify the potential association of rs833061 (-460 C>T) and rs1570360 (-1154 G>A), two SNPs of VEGF, with the risk of cSCC and the prognostic impacts on cSCC patients. MATERIAL AND METHODS This hospital-based case-control study analyzed peripheral venous blood collected from 100 cSCC patients and 124 healthy controls, and gathered personal information on patients. Genotypes of the VEGF gene -460C>T and -1154G>A polymorphism were detected using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) method. Different distributions of allele frequencies and genotype in the case and control group were measured, comparing different genotype differences in the survival of patients with cSCC. RESULTS Distributions of allele frequencies and genotype of -460 C>T in the case and control group were statistically different; the TT + CT genotype was significantly correlated with a decrease risk of cSCC (OR=0.36, 95% CI=0.21-0.63, P<0.001). There was no difference in the distribution of allele frequencies and genotype of -1154 G>A between control and case groups. For -1154460C>T, the CC genotype was an adverse factor, associated with a significant decrease in the survival status of cSCC patients (P<0.001). For VEGF-1154 G>A, the AA genotype was significantly correlated with the reduced overall survival in cSCC patients, with the mean survival time of 23.88 months (P=0.009). CONCLUSIONS The VEGF gene -460 C>T polymorphism and -1154 G>A polymorphism may serve as potential genetic markers for the risk and prognosis of cSCC.

Genomic portfolio of Merkel cell carcinoma as determined by comprehensive genomic profiling: implications for targeted therapeutics

Merkel cell carcinoma is an ultra-rare cutaneous neuroendocrine cancer for which approved treatment options are lacking. To better understand potential actionability, the genomic landscape of Merkel cell cancers was assessed. The molecular aberrations in 17 patients with Merkel cell carcinoma were, on physician request, tested in a Clinical Laboratory Improvement Amendments (CLIA) laboratory (Foundation Medicine, Cambridge, MA) using next-generation sequencing (182 or 236 genes) and analyzed by N-of-One, Inc. (Lexington, MA). There were 30 genes harboring aberrations and 60 distinct molecular alterations identified in this patient population. The most common abnormalities involved the TP53 gene (12/17 [71% of patients]) and the cell cycle pathway (CDKN2A/B, CDKN2C or RB1) (12/17 [71%]). Abnormalities also were observed in the PI3K/AKT/mTOR pathway (AKT2, FBXW7, NF1, PIK3CA, PIK3R1, PTEN or RICTOR) (9/17 [53%]) and DNA repair genes (ATM, BAP1, BRCA1/2, CHEK2, FANCA or MLH1) (5/17 [29%]). Possible cognate targeted therapies, including FDA-approved drugs, could be identified in most of the patients (16/17 [94%]). In summary, Merkel cell carcinomas were characterized by multiple distinct aberrations that were unique in the majority of analyzed cases. Most patients had theoretically actionable alterations. These results provide a framework for investigating tailored combinations of matched therapies in Merkel cell carcinoma patients.