The pleiotrophin-ALK axis is required for tumorigenicity of glioblastoma stem cells

Expression analysis of SOX2 and SOX9 in patients with oral squamous cell carcinoma

BACKGROUND

Lately SOX2 and SOX9, transcription factors associated with stemness-like phenotypes of cancer cells, have been linked to tumor growth, metastasis, and resistance to therapy.

METHODS

This study aimed on evaluating the expression of SOX2 and SOX9 in a large cohort of patients with OSCC including primary and recurrent tumors and corresponding lymph node metastases. Semiautomatic digital pathology scoring was used to determine protein expression and survival analysis was performed to evaluate its prognostic significance.

RESULTS

We found a significant downregulation of SOX9 from primary disease to lymph node metastases (p < 0.001). SOX9 expression and the subgroup SOX2lowSOX9high were significantly correlated with worse overall survival (p < 0.05). Additionally, SOX2lowSOX9high expression pattern was confirmed as independent prognosticator for overall survival.

CONCLUSIONS

These results indicate the relevant role of SOX2 and SOX9 in patients with OSCC and show the clinical relevance for further investigation on the molecular mechanisms underlying SOX-related gene expression.

Anaplastic Lymphoma Kinase Receptor: Possible Involvement in Anorexia Nervosa

The pathophysiology of Anorexia Nervosa (AN) has not been fully elucidated. Anaplastic lymphoma kinase (ALK) receptor is a protein-tyrosine kinase mainly known as a key oncogenic driver. Recently, a genetic deletion of ALK in mice has been found to increase energy expenditure and confers resistance to obesity in these animals, suggesting its role in the regulation of thinness. Here, we investigated the expression of ALK and the downstream intracellular pathways in female rats subjected to the activity-based anorexia (ABA) model, which reproduces important features of human AN. In the hypothalamic lysates of ABA rats, we found a reduction in ALK receptor expression, a downregulation of Akt phosphorylation, and no change in the extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) phosphorylation. After the recovery from body weight loss, ALK receptor expression returned to the control baseline values, while it was again suppressed during a second cycle of ABA induction. Overall, this evidence suggests a possible involvement of the ALK receptor in the pathophysiology of AN, that may be implicated in its stabilization, resistance, and/or its exacerbation.

Pharmacological targeting of the receptor ALK inhibits tumorigenicity and overcomes chemoresistance in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive disease characterized by its metastatic potential and chemoresistance. These traits are partially attributable to the highly tumorigenic pancreatic cancer stem cells (PaCSCs). Interestingly, these cells show unique features in order to sustain their identity and functionality, some of them amenable for therapeutic intervention. Screening of phospho-receptor tyrosine kinases revealed that PaCSCs harbored increased activation of anaplastic lymphoma kinase (ALK). We subsequently demonstrated that oncogenic ALK signaling contributes to tumorigenicity in PDAC patient-derived xenografts (PDXs) by promoting stemness through ligand-dependent activation. Indeed, the ALK ligands midkine (MDK) or pleiotrophin (PTN) increased self-renewal, clonogenicity and CSC frequency in several in vitro local and metastatic PDX models. Conversely, treatment with the clinically-approved ALK inhibitors Crizotinib and Ensartinib decreased PaCSC content and functionality in vitro and in vivo, by inducing cell death. Strikingly, ALK inhibitors sensitized chemoresistant PaCSCs to Gemcitabine, as the most used chemotherapeutic agent for PDAC treatment. Consequently, ALK inhibition delayed tumor relapse after chemotherapy in vivo by effectively decreasing the content of PaCSCs. In summary, our results demonstrate that targeting the MDK/PTN-ALK axis with clinically-approved inhibitors impairs in vivo tumorigenicity and chemoresistance in PDAC suggesting a new treatment approach to improve the long-term survival of PDAC patients.

Sex determining region Y-box 2 is a prognostic factor for head and neck squamous cell carcinoma: Evidence from 11 published investigations

Objective

The aim of this study was to review the published literature and investigate whether sex determining region Y-box 2 (SOX2) is a prognostic factor in head and neck squamous cell carcinoma (HNSCC) by conduct a meta-analysis.

Materials and Methods

Trials were identified from the major electronic databases (MEDLINE, EMBASE, and Cochrane Library) using the key words "HNSCC" and "SOX2." The overall survival (OS), disease-specific survival (DPS), and disease-free survival (DFS) were the primary outcome measures.

Results

We identified 371 articles, 9 articles 11 studies with a total number of 1334 cases were eligible for inclusion of this meta-analysis. The results showed that OS (DPS) in low-expression group was higher than that in high-expression group. However, the difference between the two groups was not significant (hazard ratio [HR] = 1.30, 95% confidence interval [95% CI] = [0.88, 1.91]; P = 0.18), and there was great statistical heterogeneity (I² = 66%, P = 0.002). After subgroup analysis, the HR for OS of the patients with reduced expression of SOX2 was 1.34 (95% CI = [1.04, 1.74], P = 0.03), and the heterogeneity became acceptable (I² = 32%, P = 0.16). The HR for DFS of the patients with reduced expression of SOX2 was 1.39 (95% CI = [1.00, 1.93]; P = 0.05).

Conclusion

The findings of this meta-analysis are indicative of that high SOX2 expression is a negative prognostic factor of HNSCC and exhibit both worse OS and DFS. However, the small sample size available for this systematic review limited the power of this quantitative meta-analysis. It may therefore be too early to place complete confidence in these results.

Midkine signaling maintains the self-renewal and tumorigenic capacity of glioma initiating cells

Glioblastoma (GBM) is one of the most aggressive forms of cancer. It has been proposed that the presence within these tumors of a population of cells with stem-like features termed Glioma Initiating Cells (GICs) is responsible for the relapses that take place in the patients with this disease. Targeting this cell population is therefore an issue of great therapeutic interest in neuro-oncology. We had previously found that the neurotrophic factor MIDKINE (MDK) promotes resistance to glioma cell death. The main objective of this work is therefore investigating the role of MDK in the regulation of GICs.

Methods: Assays of gene and protein expression, self-renewal capacity, autophagy and apoptosis in cultures of GICs derived from GBM samples subjected to different treatments. Analysis of the growth of GICs-derived xenografts generated in mice upon blockade of the MDK and its receptor the ALK receptor tyrosine kinase (ALK) upon exposure to different treatments.

Results: Genetic or pharmacological inhibition of MDK or ALK decreases the self-renewal and tumorigenic capacity of GICs via the autophagic degradation of the transcription factor SOX9. Blockade of the MDK/ALK axis in combination with temozolomide depletes the population of GICs in vitro and has a potent anticancer activity in xenografts derived from GICs.

Conclusions: The MDK/ALK axis regulates the self-renewal capacity of GICs by controlling the autophagic degradation of the transcription factor SOX9. Inhibition of the MDK/ALK axis may be a therapeutic strategy to target GICs in GBM patients.

Overlapping migratory mechanisms between neural progenitor cells and brain tumor stem cells

Neural stem cells present in the subventricular zone (SVZ), the largest neurogenic niche of the mammalian brain, are able to self-renew as well as generate neural progenitor cells (NPCs). NPCs are highly migratory and traverse the rostral migratory stream (RMS) to the olfactory bulb, where they terminally differentiate into mature interneurons. NPCs from the SVZ are some of the few cells in the CNS that migrate long distances during adulthood. The migratory process of NPCs is highly regulated by intracellular pathway activation and signaling from the surrounding microenvironment. It involves modulation of cell volume, cytoskeletal rearrangement, and isolation from compact extracellular matrix. In malignant brain tumors including high-grade gliomas, there are cells called brain tumor stem cells (BTSCs) with similar stem cell characteristics to NPCs but with uncontrolled cell proliferation and contribute to tumor initiation capacity, tumor progression, invasion, and tumor maintenance. These BTSCs are resistant to chemotherapy and radiotherapy, and their presence is believed to lead to tumor recurrence at distal sites from the original tumor location, principally due to their high migratory capacity. BTSCs are able to invade the brain parenchyma by utilizing many of the migratory mechanisms used by NPCs. However, they have an increased ability to infiltrate the tight brain parenchyma and utilize brain structures such as myelin tracts and blood vessels as migratory paths. In this article, we summarize recent findings on the mechanisms of cellular migration that overlap between NPCs and BTSCs. A better understanding of the intersection between NPCs and BTSCs will to provide a better comprehension of the BTSCs' invasive capacity and the molecular mechanisms that govern their migration and eventually lead to the development of new therapies to improve the prognosis of patients with malignant gliomas.

A meta-analysis on the role of pleiotrophin (PTN) as a prognostic factor in cancer

Background

Some researchers reported that pleiotrophin (PTN) is associated with the development and metastasis of various tumors and it is a poor prognostic factor for the tumor patients. However, the results of other researches are inconsistent with them. It is obliged to do a meta-analysis to reach a definite conclusion.

Methods

The published studies relevant to PTN were searched in the databases including PubMed, Embase and Web of Science until March 20, 2018. A meta-analysis was conducted to evaluate the role of PTN in clinicopathological characteristics and overall survival (OS) of cancer patients.

Results

Our meta-analysis indicated that the high expression of PTN was remarkably associated with advanced TNM stage (OR = 2.79, 95%CI: 1.92–4.06, P<0.00001) and poor OS (HR = 1.77, 95%CI: 1.41–2.22, P<0.00001) in tumor patients. The expression of PTN was not associated with tumor size (OR = 1.12, 95% CI: 0.55–2.26, P = 0.76), lymph node metastasis (LNM) (OR = 1.95, 95%CI: 0.62–6.12, P = 0.25), distant metastasis (DM) (OR = 2.78, 95%CI: 0.72–10.74, P = 0.14) and histological grade (OR = 1.95, 95%CI: 0.98–3.87, P = 0.06).

Conclusion

The high expression of PTN is significantly relevant to the advanced TNM stage and poor OS in tumor patients. PTN can serve as a promising biomarker to predict unfavorable survival outcomes, and it may be a potential target for tumor treatment.

Expression of sex-determining region Y-box protein 2 in breast cancer and its clinical significance

Sex-determining region Y-box protein 2 (SOX2) is an embryo transcription factor located on chromosome 3q26.3-q27. It plays an important role in the maintenance of differentiation and self-renewal of pluripotent stem cells. Studies have shown that SOX2 is associated with multiple cancers and is overexpressed in many different phenotypes of breast cancer. To study the relationship between SOX2 and clinicopathological parameters of breast cancer patients, we found that the expression of SOX2 was closely related to the increase in tumor size, histological grade, lymph node metastasis, and high invasiveness. Therefore, studies on the role of SOX2 in breast cancer may provide effective biomarkers and potential therapeutic targets for the diagnosis and treatment of breast cancer. This article will discuss the role of SOX2 in breast cancer, including its occurrence, invasion and metastasis, diagnosis and treatment, relapse, resistance, and prognosis.

Pleiotrophin enhances PDGFB-induced gliomagenesis through increased proliferation of neural progenitor cells

Pleiotrophin (PTN) augments tumor growth by increasing proliferation of tumor cells and promoting vascular abnormalization, but its role in early gliomagenesis has not been evaluated. Through analysis of publically available datasets, we demonstrate that increased PTN mRNA expression is associated with amplification of chromosome 7, identified as one of the earliest steps in glioblastoma development. To elucidate the role of PTN in tumor initiation we employed the RCAS/tv-a model that allows glioma induction by RCAS-virus mediated expression of oncogenes in neural progenitor cells. Intracranial injection of RCAS-PTN did not induce glioma formation when administrated alone, but significantly enhanced RCAS-platelet derived growth factor (PDGF)B-induced gliomagenesis. PTN co-treatment augmented PDGFB-induced Akt activation in neural progenitor cells in vitro, and enhanced neural sphere size associated with increased proliferation. Our data indicates that PTN expression is associated with chromosome 7 gain, and that PTN enhances PDGFB-induced gliomagenesis by stimulating proliferation of neural progenitor cells.

GBM-associated mutations and altered protein expression are more common in young patients

Background

Geriatric glioblastoma (GBM) patients have a poorer prognosis than younger patients, but IDH1/2 mutations (more common in younger patients) confer a favorable prognosis. We compared key GBM molecular alterations between an elderly (age ≥ 70) and younger (18 < = age < = 45) cohort to explore potential therapeutic opportunities.

Results

Alterations more prevalent in the young GBM cohort compared to the older cohort (P < 0.05) were: overexpression of ALK, RRM1, TUBB3 and mutation of ATRX, BRAF, IDH1, and TP53. However, PTEN mutation was significantly more frequent in older patients. Among patients with wild-type IDH1/2 status, TOPO1 expression was higher in younger patients, whereas MGMT methylation was more frequent in older patients. Within the molecularly-defined IDH wild-type GBM cohort, younger patients had significantly more mutations in PDGFRA, PTPN11, SMARCA4, BRAF and TP53.

Methods

GBMs from 178 elderly patients and 197 young patients were analyzed using DNA sequencing, immunohistochemistry, in situ hybridization, and MGMT-methylation assay to ascertain mutational and amplification/expressional status.

Conclusions

Significant molecular differences occurred in GBMs from elderly and young patients. Except for the older cohort's more frequent PTEN mutation and MGMT methylation, younger patients had a higher frequency of potential therapeutic targets.

Targeting Autophagy in ALK-Associated Cancers

Autophagy is an evolutionarily conserved catabolic process, which is used by the cells for cytoplasmic quality control. This process is induced following different kinds of stresses e.g., metabolic, environmental, or therapeutic, and acts, in this framework, as a cell survival mechanism. However, under certain circumstances, autophagy has been associated with cell death. This duality has been extensively reported in solid and hematological cancers, and has been observed during both tumor development and cancer therapy. As autophagy plays a critical role at the crossroads between cell survival and cell death, its involvement and therapeutic modulation (either activation or inhibition) are currently intensively studied in cancer biology, to improve treatments and patient outcomes. Over the last few years, studies have demonstrated the occurrence of autophagy in different Anaplastic Lymphoma Kinase (ALK)-associated cancers, notably ALK-positive anaplastic large cell lymphoma (ALCL), non-small cell lung carcinoma (NSCLC), Neuroblastoma (NB), and Rhabdomyosarcoma (RMS). In this review, we will first briefly describe the autophagic process and how it can lead to opposite outcomes in anti-cancer therapies, and we will then focus on what is currently known regarding autophagy in ALK-associated cancers.

Pleiotrophin, a target of miR-384, promotes proliferation, metastasis and lipogenesis in HBV-related hepatocellular carcinoma

Hepatitis B virus (HBV) infection plays a crucial role and is a major cause of hepatocellular carcinoma (HCC) in China. microRNAs (miRNAs) have emerged as key players in hepatic steatosis and carcinogenesis. We found that down-regulation of miR-384 expression was a common event in HCC, especially HBV-related HCC. However, the possible function of miR-384 in HBV-related HCC remains unclear. The oncogene pleiotrophin (PTN) was a target of miR-384. HBx inhibited miR-384, increasing PTN expression. The PTN receptor N-syndecan was highly expressed in HCC. PTN induced by HBx acted as a growth factor via N-syndecan on hepatocytes and further promoted cell proliferation, metastasis and lipogenesis. PTN up-regulated sterol regulatory element-binding protein 1c (SREBP-1c) through the N-syndecan/PI3K/Akt/mTORC1 pathway and the expression of lipogenic genes, including fatty acid synthesis (FAS). PTN-mediated de novo lipid synthesis played an important role in HCC proliferation and metastasis. PI3K/AKT and an mTORC1 inhibitor diminished PTN-induced proliferation, metastasis and lipogenesis. Taken together, these data strongly suggest that the dysregulation of miR-384 could play a crucial role in HBV related to HCC, and the target gene of miR-384, PTN, represents a new potential therapeutic target for the prevention of hepatic steatosis and further progression to HCC after chronic HBV infection.

Crizotinib targets in glioblastoma stem cells

Glioblastoma stem cells (GSCs) are believed to be involved in the mechanisms of tumor resistance, therapeutic failures, and recurrences after conventional glioblastoma therapy. Therefore, elimination of GSCs might be a prerequisite for the development of successful therapeutic strategies. ALK, ROS1, and MET are targeted by Crizotinib, a tyrosine kinase inhibitor which has been approved for treatment of ALK-rearranged non-small-cell lung cancer. In this study we investigated ALK, ROS1, and MET status in nine glioblastoma stem cell lines and tumors from which they arise. Fluorescent in situ hybridization (FISH), Sanger's direct sequencing, and immunohistochemistry were used to screen genomic rearrangements (or amplifications), genomic mutations, and protein expression, respectively. The immunohistochemical and FISH studies revealed no significant dysregulation of ROS1 in GSCs and associated tumors. Neither amplification nor polysomy of ALK was observed in GSC, but weak overexpression was detected by IHC in three of nine GSCs. Similarly, no MET amplification was found by FISH but three GSCs presented significant immunohistochemical staining. No ALK or MET mutation was found by Sanger's direct sequencing. In this study, we show no molecular rearrangement of ALK, ROS1, and MET that would lead us not to propose, as a valid strategy, the use of crizotinib to eradicate GSCs. However, MET was overexpressed in all GSCs with mesenchymal subtype and three GSCs presented an overexpression of ALK. Therefore, our study corroborates the idea that MET and ALK may assume a role in the tumorigenicity of GSC.

Pleiotrophin promotes chemoresistance to doxorubicin in osteosarcoma by upregulating P-glycoprotein

Chemoresistance is a major hindrance to successful treatment of osteosarcoma (OS). Pleiotrophin (PTN), a neurotrophic growth factor, has been linked to the malignant characteristics of various cancer types. We retrospectively examined the correlation between PTN expression and chemoresistance in OS in a cohort of 133 OS patients. Immunohistochemistry revealed that PTN expression correlated with the necrosis rate and local OS recurrence. In a prognostic analysis, high PTN expression was associated with poor overall and disease-free survival, and was an independent adverse prognostic factor for disease-free survival. In doxorubicin-treated OS cells, PTN knockdown enhanced cellular chemosensitivity, increased the apoptosis rate and inhibited clone formation, while PTN overexpression had the opposite effects. In a xenograft model, PTN knockdown and overexpression respectively enhanced and reduced cellular sensitivity to doxorubicin. PTN upregulated anaplastic lymphoma kinase (ALK), p-Glycogen Synthase Kinase (GSK)3β, β-catenin and multidrug resistance protein 1/P-glycoprotein (MDR1/P-gp). In rescue assays with the β-catenin inhibitor XAV939 and the MDR1/P-gp inhibitor verapamil, PTN promoted chemoresistance to doxorubicin in OS cells by activating ALK/GSK3β/β-catenin signaling, thereby upregulating MDR1/P-gp. Therefore, PTN could be used as a biomarker predicting chemotherapeutic responses, and downregulating PTN could be a promising therapeutic strategy to prevent chemoresistance in OS patients.

Tumour-associated macrophages secrete pleiotrophin to promote PTPRZ1 signalling in glioblastoma stem cells for tumour growth

Intense infiltration of tumour-associated macrophages (TAMs) facilitates malignant growth of glioblastoma (GBM), but the underlying mechanisms remain undefined. Herein, we report that TAMs secrete abundant pleiotrophin (PTN) to stimulate glioma stem cells (GSCs) through its receptor PTPRZ1 thus promoting GBM malignant growth through PTN–PTPRZ1 paracrine signalling. PTN expression correlates with infiltration of CD11b⁺/CD163⁺ TAMs and poor prognosis of GBM patients. Co-implantation of M2-like macrophages (MLCs) promoted GSC-driven tumour growth, but silencing PTN expression in MLCs mitigated their pro-tumorigenic activity. The PTN receptor PTPRZ1 is preferentially expressed in GSCs and also predicts GBM poor prognosis. Disrupting PTPRZ1 abrogated GSC maintenance and tumorigenic potential. Moreover, blocking the PTN–PTPRZ1 signalling by shRNA or anti-PTPRZ1 antibody potently suppressed GBM tumour growth and prolonged animal survival. Our study uncovered a critical molecular crosstalk between TAMs and GSCs through the PTN–PTPRZ1 paracrine signalling to support GBM malignant growth, indicating that targeting this signalling axis may have therapeutic potential.

Tumour-associated macrophages (TAMs) facilitate malignant growth of glioblastoma (GBM). Here, the authors show that TAMs support glioma stem cell renewal via paracrine signalling to the pleiotrophin receptor PTPRZ1 and that blocking this axis results in increased survival of tumour-bearing animals.

Pleiotrophin as a potential biomarker in breast cancer patients

BACKGROUND

Pleiotrophin (PTN), a multifunctional growth factor, is up-regulated in many tumors. PTN is reported to play an important role in the regulation of several cellular processes. The objective of this study is to evaluate the clinical significance of PTN as a tumor marker in breast cancer (BC).

METHODS

Serum PTN levels were detected in 105 BC patients and 40 healthy volunteers using ELISA. In addition, PTN expression was examined in 80 BC tissues in a nested case-control study by immunohistochemistry.

RESULTS

Serum PTN levels were elevated in BC patients compared to healthy controls. Area under receiver operating characteristic (ROC) curve was 0.878 (95% CI: 0.824-0.932). The sensitivity of serum PTN was superior to CEA and CA15-3. High serum PTN levels were associated with TNM stage, histology grade, and distant metastasis. Moreover, serum PTN levels decreased significantly after surgical treatment. In BC tissues, PTN expression was significantly higher in BC tissues relative to paired paracancerous tissues. Tissue PTN expression proved to be a prognostic factor for breast cancer according to multivariable logistic regression analysis.

CONCLUSION

PTN could be considered as a potential biomarker for the presence of breast cancer.

Anaplastic lymphoma kinase expression and gene alterations in glioblastoma: correlations with clinical outcome

Aims

To study anaplastic lymphoma kinase (ALK) protein expression and possible underlying gene alterations in glioblastoma (GBM), correlating them with clinical outcome.

Methods

We studied ALK immunohistochemical expression and fluorescent in situ hybridisation (FISH)-detected ALK gene alterations in 51 GBMs (46 isocitrate dehydrogenase-1 (IDH1)R132H-negative and 5 IDH-mutant (IDH1R132H-positive)). We compared two anti-ALK antibodies and immunohistochemical detection systems (5Α4/Nichirei Biosciences, D5F3/Ventana). The results were correlated with tumour cell proliferation and clinical outcome.

Results

Intense granular cytoplasmic ALK immunostaining was observed in 10/51 (19.61%) GBM and correlated with high Ki67 proliferation index; only 1 in 10 ALK-positive cases displayed multiple alk gene signals by FISH. Moderate ALK immunostaining was observed in 21 (41.17%), weak immunostaining in 5 (9.80%) while 15 (29.42%) cases were negative. p53 was expressed in 26/51 GBM (50.9%) (10% cut-off). IDH1R132H-negative GBM showed higher ALK expression compared with IDH-mutant GBM (65.2% vs 20%). ALK overexpression was more common in older patients but did not correlate with other clinicopathological variables or patient overall survival.

Conclusions

ALK overexpression can be identified in up to 70% of GBMs and does not correlate with underlying alk gene amplification. Despite being more common in rapidly growing, clinically aggressive GBM, ALK overexpression did not show correlation with prognosis in this study.

The EGF Receptor Promotes the Malignant Potential of Glioma by Regulating Amino Acid Transport System xc(-)

Extracellular free amino acids contribute to the interaction between a tumor and its microenvironment through effects on cellular metabolism and malignant behavior. System xc(-) is composed of xCT and CD98hc subunits and functions as a plasma membrane antiporter for the uptake of extracellular cystine in exchange for intracellular glutamate. Here, we show that the EGFR interacts with xCT and thereby promotes its cell surface expression and function in human glioma cells. EGFR-expressing glioma cells manifested both enhanced antioxidant capacity as a result of increased cystine uptake, as well as increased glutamate, which promotes matrix invasion. Imaging mass spectrometry also revealed that brain tumors formed in mice by human glioma cells stably overexpressing EGFR contained higher levels of reduced glutathione compared with those formed by parental cells. Targeted inhibition of xCT suppressed the EGFR-dependent enhancement of antioxidant capacity in glioma cells, as well as tumor growth and invasiveness. Our findings establish a new functional role for EGFR in promoting the malignant potential of glioma cells through interaction with xCT at the cell surface. Cancer Res; 76(10); 2954-63. ©2016 AACR.

Increased Pleiotrophin Concentrations in Papillary Thyroid Cancer

Background

Thyroid nodules are common, and approximately 5% of these nodules are malignant. Pleiotrophin (PTN) is a heparin-binding growth factor which is overexpressed in many cancers. The expression of PTN in papillary thyroid cancer (PTC) is unknown.

Method and Findings

74 subjects (age 47 ± 12 y, 15 males) who had thyroidectomy with a histological diagnosis: 79 benign nodules and 23 PTCs (10 classic, 6 tall cell, 6 follicular variant and 1 undetermined). Fine-needle aspiration (FNA) samples were obtained ex vivo from surgically excised tissue and assayed for PTN and thyroglobulin (Tg). Immunohistochemistry (IHC) was performed on tissue sections. In FNA samples, PTN concentration normalized to Tg was significantly higher in PTC than in benign nodules (16 ± 6 vs 0.3 ± 0.1 ng/mg, p < 0.001). In follicular variant of PTC (n = 6), the PTN/Tg ratio was also higher than in benign nodules (1.3 ± 0.6 vs 0.3 ± 0.1 ng/mg, P < 0.001, respectively). IHC showed cytoplasmic localization of PTN in PTC cells.

Conclusion

In ex vivo FNA samples, the PTN to thyroglobulin ratio was higher in PTCs, including follicular variant PTC, than in benign thyroid nodules. The findings raise the possibility that measurement of the PTN to Tg ratio may provide useful diagnostic and/or prognostic information in the evaluation of thyroid nodules.

Expression of SOX2 in oral squamous cell carcinoma and the association with lymph node metastasis

Oral squamous cell carcinomas (OSCCs) are a growing problem in the world. The various existing treatments have not markedly improved the survival rate of patients with OSCC during the past three decades. Novel treatment strategies are required. Sex determining region Y-box 2 (SOX2) is a transcription factor that is involved in the maintenance of embryonic stem cell pluripotency and in multiple developmental processes. SOX2 expression was indicated to act as a prognostic factor in various types of tumors, including breast, colorectal, gastric and lung cancer and glioblastoma, and as a link between malignancy and stemness. Cancer stem cells (CSCs) may be responsible for the genesis, growth and metastatic spread of tumors. The poor survival outcomes for OSCC patients may be attributable to a poor selection of target cells for treatment, as current oral cancer therapies are generally aimed at the global mass of tumor. Therefore, the consideration that novel approaches to oral cancer may be targeted using SOX2 and CSCs appears reasonable. In order to better understand the oncogenic roles and the corresponding signal transduction pathways of the SOX2 protein, the present study emphasizes the role of SOX2 in OSCC, including the proteins associated with OSCC, and reviews the literature regarding the role of SOX2 in lymph node metastasis. The aim of the present study is to provide a reference for future studies that engage in research on the aforementioned subject.

Integrative Network Analysis Combined with Quantitative Phosphoproteomics Reveals Transforming Growth Factor-beta Receptor type-2 (TGFBR2) as a Novel Regulator of Glioblastoma Stem Cell Properties

Glioblastoma is one of the most malignant brain tumors with poor prognosis and their development and progression are known to be driven by glioblastoma stem cells. Although glioblastoma stem cells lose their cancer stem cell properties during cultivation in serum-containing medium, little is known about the molecular mechanisms regulating signaling alteration in relation to reduction of stem cell-like characteristics. To elucidate the global phosphorylation-related signaling events, we performed a SILAC-based quantitative phosphoproteome analysis of serum-induced dynamics in glioblastoma stem cells established from the tumor tissues of the patient. Among a total of 2876 phosphorylation sites on 1584 proteins identified in our analysis, 732 phosphorylation sites on 419 proteins were regulated through the alteration of stem cell-like characteristics. The integrative computational analyses based on the quantified phosphoproteome data revealed the relevant changes of phosphorylation levels regarding the proteins associated with cytoskeleton reorganization such as Rho family GTPase and Intermediate filament signaling, in addition to transforming growth factor-β receptor type-2 (TGFBR2) as a prominent upstream regulator involved in the serum-induced phosphoproteome regulation. The functional association of transforming growth factor-β receptor type-2 with stem cell-like properties was experimentally validated through signaling perturbation using the corresponding inhibitors, which indicated that transforming growth factor-β receptor type-2 could play an important role as a novel cell fate determinant in glioblastoma stem cell regulation.

The glioblastoma vasculature as a target for cancer therapy

Glioblastoma is characterized by microvascular proliferation and a highly abnormal dysfunctional vasculature. The glioblastoma vessels differ significantly from normal brain vessels morphologically, functionally and molecularly. The present review provides a brief overview of the current understanding of the formation, functional abnormalities and specific gene expression of glioblastoma vessels and the consequences of vascular abnormalization for the tumour microenvironment.

Thr160 of Axin1 is critical for the formation and function of the β-catenin destruction complex

Upon binding of a Wnt ligand to the frizzled (FZD)-low density lipoprotein receptor related protein 5/6 (LRP5/6) receptor complex, the β-catenin destruction complex, composed of Axin1, adenomatous polyposis coli (APC), glycogen synthase kinase 3 (GSK3) and casein kinase 1 (CK1), is immediately inactivated, which causes β-catenin stabilization. However, the molecular mechanism of signal transduction from the receptor complex to the β-catenin destruction complex is controversial. Here we show that Wnt3a treatment promotes the dissociation of the Axin1-APC complex in glioblastoma cells cultured in serum-free medium. Experiments with the GSK3 inhibitor BIO suggest that Axin1-APC dissociation was controlled by phosphorylation. Introduction of a phosphomimetic mutation into Thr160 of Axin1, located in the APC-binding region RGS, abrogated the interaction of Axin1 with APC. Consistent with these observations, the Axin1 phosphomimetic mutant lost the ability to reduce β-catenin stability and to repress β-catenin/TCF-dependent transcription. Taken together, our results suggest a novel mechanism of Wnt signaling through the dissociation of the β-catenin destruction complex by Axin1 Thr160 modification.

Systemic treatment in EGFR-ALK NSCLC patients: second line therapy and beyond

Lung cancer is the most frequently diagnosed cancer and a leading cause of cancer mortality worldwide, with adenocarcinoma being the most common histological subtype. Deeper understanding of the pathobiology of non-small cell lung cancer (NSCLC) has led to the development of small molecules that target genetic mutations known to play critical roles in progression to metastatic disease and to influence response to targeted therapies. The principle goal of precision medicine is to define those patient populations most likely to respond to targeted therapies. However, the cancer genome landscape is composed of relatively few "mountains" [representing the most commonly mutated genes like KRAS, epidermal growth factor (EGFR), and anaplastic lymphoma kinase (ALK)] and a vast number of "hills" (representing low frequency but potentially actionable mutations). Low-frequency lesions that affect a druggable gene product allow a relatively small population of cancer patients for targeted therapy to be selected.

GDC-0980-induced apoptosis is enhanced by autophagy inhibition in human pancreatic cancer cells

Pancreatic cancer remains fatal to the fast majority of affected patients. Activation of phosphoinositide-3 kinase (PI3K)-AKT-mammalian target of rapamycin (mTOR) pathway plays an important role in pancreatic cancer progression and chemo-resistance. In the present study, we examined the activity of GDC-0980, a novel class I PI3K/mTOR kinase inhibitor, against pancreatic cancer cells in vitro. GDC-0980 inhibited AKT-mTOR activation and pancreatic cancer cell (PANC-1 and Capan-1 lines) survival. In both cancer cell lines, GDC-0980 simultaneously activated apoptosis and autophagy, the latter was detected by p62 degradation, Beclin-1 upregulation and light chain 3B (LC3B) conversion from a cytosolic (LC3B-I) to a membrane-bound (LC3B-II) form. Autophagy inhibitors including 3-methyladenine, hydroxychloroquine, NH4Cl and bafilomycin A1 enhanced apoptosis and cytotoxicity by GDC-0980, such an effect was reversed by caspase inhibitors (z-VAD-FMK and z-ITED-FMK). Furthermore, knockdown of LC3B or Beclin-1 through siRNA increased GDC-0980-induced anti-pancreatic cancer cell activity. Thus, inhibition of autophagy sensitizes GDC-0980-induced anti-pancreatic cancer activity, suggesting a novel therapeutic strategy for GDC-0980 sensitization.

ALK-driven tumors and targeted therapy: focus on crizotinib

Receptor tyrosine kinases have emerged as promising therapeutic targets for a diverse set of tumors. Overactivation of the tyrosine kinase anaplastic lymphoma kinase (ALK) has been reported in several types of malignancies such as anaplastic large cell lymphoma, inflammatory myofibroblastic tumor, neuroblastoma, and non-small-cell lung carcinoma. Further characterization of the molecular role of ALK has revealed an oncogenic signaling signature that results in tumor dependence on ALK. ALK-positive tumors display a different behavior than their ALK-negative counterparts; however, the specific role of ALK in some of these tumors remains to be elucidated. Although more studies are required to establish selective targeting of ALK as a definitive therapeutic option, initial trials have shown extraordinary results in the majority of cases.

ALK as a paradigm of oncogenic promiscuity: different mechanisms of activation and different fusion partners drive tumors of different lineages

Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase protein implicated in a variety of hematological malignancies and solid tumors. Since the identification of the ALK gene in 1994 as the target of the t(2;5) chromosomal translocation in anaplastic large cell lymphoma, ALK has been proven a remarkably promiscuous oncogene. ALK contributes to the development of a notable assortment of tumor types from different lineages, including hematolymphoid, mesenchymal, epithelial and neural tumors, through a variety of genetic mechanisms: gene fusions, activating point mutations, and gene amplification. Recent developments led to significant diagnostic and therapeutic advances, including efficient diagnostic tests and ALK-targeting agents readily available in the clinical setting. This review addresses some therapeutic considerations of ALK-targeted agents and the biologic implications of ALK oncogenic promiscuity, but the main points discussed are: 1) the variety of mechanisms that result in activation of the ALK oncogene, with emphasis on the promiscuous partnerships demonstrated in chromosomal rearrangements; 2) the diversity of tumor types of different lineages in which ALK has been implicated as a pathogenic driver; and 3) the different diagnostic tests available to identify ALK-driven tumors, and their respective indications.