Expression and clinical significance of tyrosine phosphatase SHP2 in thyroid carcinoma

Tyrosine phosphatase PTPN11/SHP2 in solid tumors - bull's eye for targeted therapy?

Encoded by PTPN11, the Src-homology 2 domain-containing phosphatase 2 (SHP2) integrates signals from various membrane-bound receptors such as receptor tyrosine kinases (RTKs), cytokine and integrin receptors and thereby promotes cell survival and proliferation. Activating mutations in the PTPN11 gene may trigger signaling pathways leading to the development of hematological malignancies, but are rarely found in solid tumors. Yet, aberrant SHP2 expression or activation has implications in the development, progression and metastasis of many solid tumor entities. SHP2 is involved in multiple signaling cascades, including the RAS-RAF-MEK-ERK-, PI3K-AKT-, JAK-STAT- and PD-L1/PD-1- pathways. Although not mutated, activation or functional requirement of SHP2 appears to play a relevant and context-dependent dichotomous role. This mostly tumor-promoting and infrequently tumor-suppressive role exists in many cancers such as gastrointestinal tumors, pancreatic, liver and lung cancer, gynecological entities, head and neck cancers, prostate cancer, glioblastoma and melanoma. Recent studies have identified SHP2 as a potential biomarker for the prognosis of some solid tumors. Based on promising preclinical work and the advent of orally available allosteric SHP2-inhibitors early clinical trials are currently investigating SHP2-directed approaches in various solid tumors, either as a single agent or in combination regimes. We here provide a brief overview of the molecular functions of SHP2 and collate current knowledge with regard to the significance of SHP2 expression and function in different solid tumor entities, including cells in their microenvironment, immune escape and therapy resistance. In the context of the present landscape of clinical trials with allosteric SHP2-inhibitors we discuss the multitude of opportunities but also limitations of a strategy targeting this non-receptor protein tyrosine phosphatase for treatment of solid tumors.

High expression of SHP2 predicts a promising prognosis in colorectal cancer

Background

Src homology 2 domain-containing phosphatase 2 (SHP2) is hyper-activated in some solid tumors. Previous findings suggest that the expression of SHP2 in colorectal cancer (CRC) may be associated with prognosis. However, validation with large sample data is lacking. Materials and Methods: Tissue microarrays containing 860 CRCs and 197 mucosal tissues adjacent to the tumors were constructed. Immunohistochemistry was used to evaluate the expression of SHP2. Differences between SHP2 expression and clinicopathological parameters were evaluated. Kaplan-Meier survival curves and log-rank tests were used to analyze the relationships between SHP2 expression and the overall survival of patients. A Cox proportional hazard regression model was used for univariate and multivariate analyses of prognostic factors.

Results

SHP2 expression in CRCs tissues was significantly higher than those in adjacent mucosal tissues (P < 0.001). SHP2 expression was related to tumor differentiation, depth of invasion, distant metastasis, vascular tumor thrombus, lymph node metastasis, and TNM classification (P < 0.05). The prognosis of the high-expression group of SHP2 was significantly better than that of the low-expression group (P = 0.008). Univariate analysis showed that the expression of SHP2 was a prognostic factor for CRC (P = 0.008). Multivariate analysis demonstrated that SHP2 remained an independent prognostic factor for CRC (P = 0.033).

Conclusion

The expression of SHP2 was significantly higher in CRC tissues than in adjacent normal tissues. High expression of SHP2 was associated with a promising outcome, suggesting that SHP2 may be a favorable prognostic indicator of CRC.

Nanomaterials: a promising multimodal theranostics platform for thyroid cancer

Thyroid cancer is the most prevalent malignant neoplasm of the cervical region and endocrine system, characterized by a discernible upward trend in incidence over recent years. Ultrasound-guided fine needle aspiration is the current standard for preoperative diagnosis of thyroid cancer, albeit with limitations and a certain degree of false-negative outcomes. Although differentiated thyroid carcinoma generally exhibits a favorable prognosis, dedifferentiation is associated with an unfavorable clinical course. Anaplastic thyroid cancer, characterized by high malignancy and aggressiveness, remains an unmet clinical need with no effective treatments available. The emergence of nanomedicine has opened new avenues for cancer theranostics. The unique features of nanomaterials, including multifunctionality, modifiability, and various detection modes, enable non-invasive and convenient thyroid cancer diagnosis through multimodal imaging. For thyroid cancer treatment, nanomaterial-based photothermal therapy or photodynamic therapy, combined with chemotherapy, radiotherapy, or gene therapy, holds promise in reducing invasiveness and prolonging patient survival or alleviating pain in individuals with anaplastic thyroid carcinoma. Furthermore, nanomaterials enable simultaneous diagnosis and treatment of thyroid cancer. This review aims to provide a comprehensive survey of the latest developments in nanomaterials for thyroid cancer diagnosis and treatment and encourage further research in developing innovative and effective theranostic approaches for thyroid cancer.

Follicular Thyroid Adenoma and Follicular Thyroid Carcinoma-A Common or Distinct Background? Loss of Heterozygosity in Comprehensive Microarray Study

Pre- and postsurgical differentiation between follicular thyroid adenoma (FTA) and follicular thyroid cancer (FTC) represents a significant diagnostic challenge. Furthermore, it remains unclear whether they share a common or distinct background and what the mechanisms underlying follicular thyroid lesions malignancy are. The study aimed to compare FTA and FTC by the comprehensive microarray and to identify recurrent regions of loss of heterozygosity (LOH). We analyzed formalin-fixed paraffin-embedded (FFPE) samples acquired from 32 Caucasian patients diagnosed with FTA (16) and FTC (16). We used the OncoScan™ microarray assay (Affymetrix, USA), using highly multiplexed molecular inversion probes for single nucleotide polymorphism (SNP). The total number of LOH was higher in FTC compared with FTA (18 vs. 15). The most common LOH present in 21 cases, in both FTA (10 cases) and FTC (11 cases), was 16p12.1, which encompasses many cancer-related genes, such as TP53, and was followed by 3p21.31. The only LOH present exclusively in FTA patients (56% vs. 0%) was 11p11.2-p11.12. The alteration which tended to be detected more often in FTC (6 vs. 1 in FTA) was 12q24.11-q24.13 overlapping FOXN4, MYL2, PTPN11 genes. FTA and FTC may share a common genetic background, even though differentiating rearrangements may also be detected.

Targeting SHP2 sensitizes differentiated thyroid carcinoma to the MEK inhibitor

Pharmacologic targeting of components of the MAPK/ERK pathway in differentiated thyroid carcinoma (DTC) is often limited due to the development of adaptive resistance. However, the detailed mechanism of MEK inhibitor (MEKi) resistance is not fully understood. Here, MEKi-resistant models were constructed successfully, in which multiple receptor tyrosine kinases (RTKs) signaling pathways and Src-homology 2 domain-containing phosphatase 2 (SHP2) were activated in MEKi-resistant cells. Given the physiological role of SHP2 as the downstream target of many RTKs, we first found blockade of SHP2 enhanced the sensitivity to MEKi in constructed MEKi-resistant models. Interestingly, we also found that compared with MEKi treatment alone, MEKi in combination with an SHP2 inhibitor markedly suppressed the reactivation of the MEK/ERK pathway; thus, the addition of the SHP2 inhibitor significantly improved the antitumor effects of MEKi. The synergistic suppression of DTC upon treatment with both inhibitors was further confirmed in xenograft models and transgenic models. Thus, our data suggest that RTKs activation leads to reactivation of the MAPK pathway and resistance to MEKi in DTC, which is reversed by SHP2 blockade. As a novel active inhibitor of SHP2, SHP099 in combination with MEKi is a promising therapeutic approach for advanced DTC and MEKi-resistant one.

Next-Generation Molecular Imaging of Thyroid Cancer

An essential aspect of thyroid cancer (TC) management is personalized and precision medicine. Functional imaging of TC with radioiodine and [18F]FDG has been frequently used in disease evaluation for several decades now. Recently, advances in molecular imaging have led to the development of novel tracers based on aptamer, peptide, antibody, nanobody, antibody fragment, and nanoparticle platforms. The emerging targets-including HER2, CD54, SHP2, CD33, and more-are promising targets for clinical translation soon. The significance of these tracers may be realized by outlining the way they support the management of TC. The provided examples focus on where preclinical investigations can be translated. Furthermore, advances in the molecular imaging of TC may inspire the development of novel therapeutic or theranostic tracers. In this review, we summarize TC-targeting probes which include transporter-based and immuno-based imaging moieties. We summarize the most recent evidence in this field and outline how these emerging strategies may potentially optimize clinical practice.

PD-1 blockade delays tumor growth by inhibiting an intrinsic SHP2/Ras/MAPK signalling in thyroid cancer cells

BACKGROUND

The programmed cell death-1 (PD-1) receptor and its ligands PD-L1 and PD-L2 are immune checkpoints that suppress anti-cancer immunity. Typically, cancer cells express the PD-Ls that bind PD-1 on immune cells, inhibiting their activity. Recently, PD-1 expression has also been found in cancer cells. Here, we analysed expression and functions of PD-1 in thyroid cancer (TC).

METHODS

PD-1 expression was evaluated by immunohistochemistry on human TC samples and by RT-PCR, western blot and FACS on TC cell lines. Proliferation and migration of TC cells in culture were assessed by BrdU incorporation and Boyden chamber assays. Biochemical studies were performed by western blot, immunoprecipitation, pull-down and phosphatase assays. TC cell tumorigenicity was assessed by xenotransplants in nude mice.

RESULTS

Human TC specimens (47%), but not normal thyroids, displayed PD-1 expression in epithelial cells, which significantly correlated with tumour stage and lymph-node metastasis. PD-1 was also constitutively expressed on TC cell lines. PD-1 overexpression/stimulation promoted TC cell proliferation and migration. Accordingly, PD-1 genetic/pharmacologic inhibition caused the opposite effects. Mechanistically, PD-1 recruited the SHP2 phosphatase to the plasma membrane and potentiated its phosphatase activity. SHP2 enhanced Ras activation by dephosphorylating its inhibitory tyrosine 32, thus triggering the MAPK cascade. SHP2, BRAF and MEK were necessary for PD-1-mediated biologic functions. PD-1 inhibition decreased, while PD-1 enforced expression facilitated, TC cell xenograft growth in mice by affecting tumour cell proliferation.

CONCLUSIONS

PD-1 circuit blockade in TC, besides restoring anti-cancer immunity, could also directly impair TC cell growth by inhibiting the SHP2/Ras/MAPK signalling pathway.

Oncogenic Tyrosine Phosphatases: Novel Therapeutic Targets for Melanoma Treatment

Despite a large number of therapeutic options available, malignant melanoma remains a highly fatal disease, especially in its metastatic forms. The oncogenic role of protein tyrosine phosphatases (PTPs) is becoming increasingly clear, paving the way for novel antitumor treatments based on their inhibition. In this review, we present the oncogenic PTPs contributing to melanoma progression and we provide, where available, a description of new inhibitory strategies designed against these enzymes and possibly useful in melanoma treatment. Considering the relevance of the immune infiltrate in supporting melanoma progression, we also focus on the role of PTPs in modulating immune cell activity, identifying interesting therapeutic options that may support the currently applied immunomodulating approaches. Collectively, this information highlights the value of going further in the development of new strategies targeting oncogenic PTPs to improve the efficacy of melanoma treatment.

PTPN11 Knockdown Prevents Changes in the Expression of Genes Controlling Cell Cycle, Chemotherapy Resistance, and Oncogene-Induced Senescence in Human Thyroid Cells Overexpressing BRAF V600E Oncogenic Protein

The MAPK (RAS/BRAF/MEK/ERK) signaling pathway is a kinase cascade involved in the regulation of cell proliferation, differentiation, and survival in response to external stimuli. The V600E mutation in the BRAF gene has been detected in various tumors, resulting in a 500-fold increase in BRAF kinase activity. However, monotherapy with selective BRAF V600E inhibitors often leads to reactivation of MAPK signaling cascade and emergence of drug resistance. Therefore, new targets are being developed for the inhibition of components of the aberrantly activated cascade. It was recently discovered that resistance to BRAF V600E inhibitors may be associated with the activity of the tyrosine phosphatase SHP-2 encoded by the PTPN11 gene. In this paper, we analyzed transcriptional effects of PTPN11 gene knockdown and selective suppression of BRAF V600E in a model of thyroid follicular epithelium. We found that the siRNA-mediated knockdown of PTPN11 after vemurafenib treatment prevented an increase in the expression CCNA1 and NOTCH4 genes involved in the formation of drug resistance of tumors. On the other hand, downregulation of PTPN11 expression blocked the transcriptional activation of genes (p21, p15, p16, RB1, and IGFBP7) involved in cell cycle regulation and oncogene-induced senescence in response to BRAF V600E expression. Therefore, it can be assumed that SHP-2 participates not only in emergence of drug resistance in cancer cells, but also in oncogene-induced cell senescence.

PTPN11 hypomethylation is associated with gastric cancer progression

Protein tyrosine phosphatase non-receptor type 11 (PTPN11) encodes the tyrosine phosphatase SHP-2 that is overexpressed in gastric cancer (GC). In the present study, the association of PTPN11 methylation levels with the incidence of GC and its correlation with SHP-2 overexpression were investigated. The methylation levels of PTPN11 in tumor and adjacent normal tissues of 112 GC patients were assessed by quantitative methylation specific PCR (qMSP). The Cancer Genome Atlas (TCGA) public database was used to analyze the association between PTPN11 methylation and PTPN11 expression. Survival analyses were conducted in order to evaluate the prognostic value of PTPN11 methylation for GC. The results of the qMSP analysis indicated that the methylation levels of PTPN11 in GC tumor tissues were significantly decreased compared with those noted in the normal adjacent tissues (mean with standard deviation: 40.91±26.33 vs. 51.99±37.37, P=0.007). An inverse correlation between PTPN11 methylation levels and PTPN11 mRNA expression levels (P=4×10^-6, r=-0.237) was noted. Subgroup analyses indicated that the association of PTPN11 hypomethylation with the incidence of GC was specific to male subjects (P=0.015), heavy drinking patients (P=0.019), patients with poor tumor differentiation (P=0.010) and patients with tumor node and metastasis (TNM) stage III+IV (P=0.008). Kaplan-Meier analyses and log-rank test suggested that PTPN11 hypomethylation was not associated with GC patient overall survival (P=0.605) and recurrence (P=0.485), although it could predict the recurrence of GC patients up to and including 60 years (≤60, P=0.049). The results indicated that PTPN11 levels were hypomethylated in GC patients. TCGA data analysis suggested that PTPN11 hypomethylation could cause an upregulation in the transcription levels of PTPN11. Although, this may explain the pattern of SHP-2 overexpression in GC, additional studies are required to verify this hypothesis. The association of PTPN11 hypomethylation with GC incidence may be specific to male patients, heavy drinking patients, patients with poor tumor differentiation and patients with TNM stage of III+IV. PTPN11 hypomethylation can be considered a biomarker for the recurrence of GC patients with an age of 60 years or lower.

Shp2 expression is upregulated in cervical cancer, and Shp2 contributes to cell growth and migration and reduces sensitivity to cisplatin in cervical cancer cells

Src homology phosphotyrosine phosphatase 2 (Shp2) has been found to be overexpressed in cervical cancer tissues. However, the influence of Shp2 on the biological behavior and sensitivity to cisplatin of cervical cancer cells remains unclear. We aimed to assess Shp2 expression in cervical tissues and cell lines and to detect the influence of Shp2 knockdown and overexpression on the biological behavior and sensitivity to cisplatin in cervical cancer cells. We found that Shp2 expression was significantly upregulated in cervical cancer tissues and cell lines, and Shp2 overexpression was associated with lymph node metastasis and a high human papillomavirus (HPV) DNA load. Shp2 knockdown inhibited cell growth and migration and enhanced sensitivity to cisplatin in the HeLa and SiHa cervical cancer cell lines. In contrast, Shp2 overexpression had the opposite effects. These tumor-promoting effects of Shp2 may be partly related to Akt signaling. In conclusion, Shp2 is involved in the occurrence and development of cervical cancer and may confer cisplatin resistance in cervical cancer. Shp2 blockade may be a new strategy for cervical cancer treatment.

Clinicopathological and prognostic significance of SHP2 and Hook1 expression in patients with thyroid carcinoma

Some thyroid carcinomas (TCs) have an aggressive biological behavior and poor prognosis, and lacking of effective molecular markers is still the main obstacle for clinical stratified diagnosis and treatment of TC. The aim of the study was to discover the clinicopathological and prognostic implications of Src homology region 2-containing protein tyrosine phosphatase 2 (SHP2) and Hook microtubule tethering protein 1 (Hook1) expression in TC. The expression of SHP2 and Hook1 was detected by immunohistochemistry on tissue microarrays from 313 primary TCs who underwent surgery in January 2006 and January 2010 in Zhejiang Cancer Hospital. The χ² test, Kaplan-Meier method, and Cox proportional-hazards regression models were used to analyze the associations between their expressions and clinicopathological features and prognosis. The expression rates of SHP2 and Hook1 in TC were 57.5% (180/313) and 22.0% (69/313), respectively. SHP2 was positively correlated with Hook1 in TC. SHP2 expression differed significantly by age, histologic variants, maximal tumor diameter, intrathyroidal dissemination, metastases, and disease stage (P < .05). Moreover, patients with high SHP2 expression had reduced risk for death of disease compared with those with low SHP2 expression (hazard ratio, 0.267; 95% confidence interval, 0.105-0.684; P = .006) in univariate analysis, but that multivariate analysis failed to suggest that SHP2 was an independent prognostic factor. Hook1 expression differed significantly by histologic variants, maximal tumor diameter, and intrathyroidal dissemination (P < .05). However, there was no significant correlation between Hook1 expression and outcome in TC (P > .05). Our results suggested that SHP2 may be a favorable indicator of prognosis in TC.

Thyroid Cancer Detection by Ultrasound Molecular Imaging with SHP2-Targeted Perfluorocarbon Nanoparticles

Background

Contrast-enhanced ultrasound imaging has been widely used in the ultrasound diagnosis of a variety of tumours with high diagnostic accuracy, especially in patients with hepatic carcinoma, while its application is rarely reported in thyroid cancer. The currently used ultrasound contrast agents, microbubbles, cannot be targeted to molecular markers expressed in tumour cells due to their big size, leading to a big challenge for ultrasound molecular imaging. Phase-changeable perfluorocarbon nanoparticles may resolve the penetrability limitation of microbubbles and serve as a promising probe for ultrasound molecular imaging.

Methods

65 thyroid tumour samples and 40 normal samples adjacent to thyroid cancers were determined for SHP2 expression by IHC. SHP2-targeted PLGA nanoparticles (NPs-SHP2) encapsulating perfluoropentane (PFP) were prepared with PLGA-PEG as a shell material, and their specific target-binding ability was assessed in vitro and in vivo, and the effect on the enhancement of ultrasonic imaging induced by LIFU was studied in vivo.

Results

In the present study, we verified that tumour overexpression of SHP2 and other protein tyrosine phosphatases regulated several cellular processes and contributed to tumorigenesis, which could be introduced to ultrasound molecular imaging for differentiating normal from malignant thyroid diagnostic nodes. The IHC test showed remarkably high expression of SHP2 in human thyroid carcinoma specimens. In thyroid tumour xenografts in mice, the imaging signal was significantly enhanced by SHP2-targeted nanoparticles after LIFU induction.

Conclusion

This study provides a basis for preclinical exploration of ultrasound molecular imaging with NPs-SHP2 for clinical thyroid nodule detection to enhance diagnostic accuracy.

Stepping out of the shadows: Oncogenic and tumor-promoting protein tyrosine phosphatases

Protein tyrosine phosphorylation is critical for proper function of cells and organisms. Phosphorylation is regulated by the concerted but generically opposing activities of tyrosine kinases (PTKs) and tyrosine phosphatases (PTPs), which ensure its proper regulation, reversibility, and ability to respond to changing physiological situations. Historically, PTKs have been associated mainly with oncogenic and pro-tumorigenic activities, leading to the generalization that protein dephosphorylation is anti-oncogenic and hence that PTPs are tumor-suppressors. In many cases PTPs do suppress tumorigenesis. However, a growing body of evidence indicates that PTPs act as dominant oncogenes and drive cell transformation in a number of contexts, while in others PTPs support transformation that is driven by other oncogenes. This review summarizes the known transforming and tumor-promoting activities of the classical, tyrosine specific PTPs and highlights their potential as drug targets for cancer therapy.

SHP-2在结直肠癌组织中的表达及临床意义

目的

探讨SHP-2蛋白在结直肠癌中的表达情况及其与病理特征的关系.

方法

采用免疫组织化学法和Western blot方法检测SHP-2蛋白在人结直肠癌组织中的表达情况, 分析其与患者临床病理因素的关系.

结果

结直肠癌组织中SHP-2阳性表达率为25.6%(43/168), 与正常结直肠组织比较, 差异有统计学意义(P<0.05). 结直肠癌组织中SHP-2的蛋白水平为0.2396±0.0655, 与配对正常结直肠组织比较(0.7665±0.1133), 差异有统计学意义(P<0.0001). SHP-2蛋白的低表达与分化程度和淋巴结转移有关, 与性别、年龄、浸润程度、远处转移、TNM分期无关.

结论

SHP-2可能在结直肠癌的发生发展过程中起抑制作用, 并可能成为潜在的治疗靶点.

SHP2 overexpression enhances the invasion and metastasis of ovarian cancer in vitro and in vivo

Purpose

SHP2 has roles in a variety of signal transduction pathways and in many important cellular processes, including proliferation, differentiation, movement regulation, and apoptosis. In addition, SHP2 expression is closely associated with multiple types of malignancies. In this study, we examined the role of SHP2 in epithelial ovarian cancer.

Patients and methods

SHP2 expression in cancer and normal ovarian tissue specimens was evaluated by immunohistochemical staining and Western blot analyses. The correlation between the SHP2 expression level and clinicopathological features was analyzed. The role of SHP2 in epithelial ovarian cancer was evaluated by assessing SHP2 expression patterns in vitro and in vivo, and activation of the PI3K/AKT pathway was examined.

Results

SHP2 is expressed at higher levels in ovarian cancer tissues than in normal ovarian tissues and in an ovarian cancer cell line than in a normal ovarian cell line. On the basis of these findings, SHP2 is overexpressed in ovarian cancer both in vitro and in vivo. In addition, SHP2 overexpression is associated with tumor stage and differentiation, enhanced cell proliferation and invasion, and tumorigenesis and metastasis.

Conclusion

SHP2 overexpression enhances ovarian tumor proliferation and invasion by activating the PI3K-AKT axis, indicating that SHP2 potentially plays a direct role in the pathogenesis of ovarian epithelial cell cancer. These novel findings provide key insights that are applicable to basic cancer research and to the prevention and treatment of cancer.

Integrating omics data and protein interaction networks to prioritize driver genes in cancer

Although numerous approaches have been proposed to discern driver from passenger, identification of driver genes remains a critical challenge in the cancer genomics field. Driver genes with low mutated frequency tend to be filtered in cancer research. In addition, the accumulation of different omics data necessitates the development of algorithmic frameworks for nominating putative driver genes. In this study, we presented a novel framework to identify driver genes through integrating multi-omics data such as somatic mutation, gene expression, and copy number alterations. We developed a computational approach to detect potential driver genes by virtue of their effect on their neighbors in network. Application to three datasets (head and neck squamous cell carcinoma (HNSC), thyroid carcinoma (THCA) and kidney renal clear cell carcinoma (KIRC)) from The Cancer Genome Atlas (TCGA), by comparing the Precision, Recall and F1 score, our method outperformed DriverNet and MUFFINN in all three datasets. In addition, our method was less affected by protein length compared with DriverNet. Lastly, our method not only identified the known cancer genes but also detected the potential rare drivers (PTPN6 in THCA, SRC, GRB2 and PTPN6 in KIRC, MAPK1 and SMAD2 in HNSC).

LNDriver: identifying driver genes by integrating mutation and expression data based on gene-gene interaction network

BACKGROUND

Cancer is a complex disease which is characterized by the accumulation of genetic alterations during the patient's lifetime. With the development of the next-generation sequencing technology, multiple omics data, such as cancer genomic, epigenomic and transcriptomic data etc., can be measured from each individual. Correspondingly, one of the key challenges is to pinpoint functional driver mutations or pathways, which contributes to tumorigenesis, from millions of functional neutral passenger mutations.

RESULTS

In this paper, in order to identify driver genes effectively, we applied a generalized additive model to mutation profiles to filter genes with long length and constructed a new gene-gene interaction network. Then we integrated the mutation data and expression data into the gene-gene interaction network. Lastly, greedy algorithm was used to prioritize candidate driver genes from the integrated data. We named the proposed method Length-Net-Driver (LNDriver).

CONCLUSIONS

Experiments on three TCGA datasets, i.e., head and neck squamous cell carcinoma, kidney renal clear cell carcinoma and thyroid carcinoma, demonstrated that the proposed method was effective. Also, it can identify not only frequently mutated drivers, but also rare candidate driver genes.

SHP2 phosphatase as a novel therapeutic target for melanoma treatment

Melanoma ranks among the most aggressive and deadly human cancers. Although a number of targeted therapies are available, they are effective only in a subset of patients and the emergence of drug resistance often reduces durable responses. Thus there is an urgent need to identify new therapeutic targets and develop more potent pharmacological agents for melanoma treatment. Herein we report that SHP2 levels are frequently elevated in melanoma, and high SHP2 expression is significantly associated with more metastatic phenotype and poorer prognosis. We show that SHP2 promotes melanoma cell viability, motility, and anchorage-independent growth, through activation of both ERK1/2 and AKT signaling pathways. We demonstrate that SHP2 inhibitor 11a-1 effectively blocks SHP2-mediated ERK1/2 and AKT activation and attenuates melanoma cell viability, migration and colony formation. Most importantly, SHP2 inhibitor 11a-1 suppresses xenografted melanoma tumor growth, as a result of reduced tumor cell proliferation and enhanced tumor cell apoptosis. Taken together, our data reveal SHP2 as a novel target for melanoma and suggest SHP2 inhibitors as potential novel therapeutic agents for melanoma treatment.