Akt activation and localisation correlate with tumour invasion and oncogene expression in thyroid cancer

Proteomic analysis reveals modulation of key proteins in follicular thyroid cancer progression

BACKGROUND

Cytopathology cannot be used to reliably distinguish follicular thyroid adenoma (FTA) from follicular thyroid carcinoma (FTC), the second most common form of thyroid cancer, because they exhibit nearly identical cellular morphology. Given the challenges in diagnosis and treatment, this study aims to identify the mechanisms underlying FTC is essential.

METHODS

Using parallel reaction monitoring-mass spectrometry (PRM-MS) assays, we identified and quantified 94 differentially expressed protein candidates from a retrospective cohort of 1085 FTC and FTA tissue samples from 18 clinical centers. Of these targeted proteins, those with the potential for distinguishing FTC from FTA were prioritized using machine learning. Co-immunoprecipitation (co-IP) and immunofluorescence co-localization assays, as well as gene interference, overexpression, and immunohistochemistry (IHC) experiments, were used to investigate the interactions and cellular functions of selected proteins.

RESULTS

Using machine learning models and feature selection methods, 30 of the 94 candidates were prioritized as key proteins. Co-IP and immunofluorescence co-localization assays using FTC cell lines revealed interactions among insulin-like growth factor 2 receptor (IGF2R), major vault protei (MVP), histone deacetylase 1 (HDAC1), and histone H1.5 (H1-5). Gene interference and overexpression experiments in FTC-133 cells confirmed the promotional role of these proteins in cell proliferation. IHC assays of patient samples further confirmed elevated expression of these four proteins in FTC compared with that in FTA.

CONCLUSIONS

Our findings underscore the utility of advanced proteomic techniques in elucidating the molecular underpinnings of FTC, highlighting the potential significance of IGF2R, MVP, HDAC1, and H1-5 in FTC progression, and providing a foundation for the exploration of targeted therapies.

Extra-nuclear TERT counteracts oxidative stress and promotes progression in papillary thyroid carcinoma

The reactivation of TERT is associated with poor outcome in papillary thyroid cancer (PTC). Extra-telomeric functions of TERT were reported, with a protective role against oxidative stress (OS). The aim of the present study was to explore the extra-nuclear TERT localization in PTC and its role in cancer progression. TERT nuclear export under OS were analyzed in K1 PTC cell line. We investigated the role of different TERT localizations using specific TERT constructs that limit its localization to the nucleus or to the mitochondria. The effect of SRC kinase inhibitor PP2, which reduces TERT nuclear export, was investigated as well. Moreover, TERT localization was analyzed in 39 PTC tissues and correlated with the genetic profile and the level of OS, DNA damage and apoptosis in the tumors and with the clinical characteristics of the patients. We demonstrated that TERT is exported from the nucleus in response to OS induced either from H2O2 or the BRAF inhibitor PLX4720. We proved that extra-nuclear TERT reduces mitochondrial OS and induces mitochondrial fragmentation. Moreover, limiting mitochondrial TERT localization reduced proliferation, migration, AKT phosphorylation and glycolysis and increased DNA damage and p21 expression. Finally, in PTC tissues the fraction of mitochondrial/nuclear TERT resulted inversely correlated with OS and p21 expression and associated with tumor persistence. In conclusion, our data indicate that extra-nuclear TERT is involved in reducing the effect of excessive OS, thus promoting cancer cell survival. Extra-nuclear TERT may thus represent a marker of cancer progression and a possible therapeutic target in PTC.

The Role of Inositols in Endocrine and Neuroendocrine Tumors

Inositols have demonstrated a role in cancer prevention and treatment in many kinds of neoplasms. Their molecular mechanisms vary from the regulation of survival and proliferative pathways to the modulation of immunity and oxidative stress. The dysregulation of many pathways and mechanisms regulated by inositols has been demonstrated in endocrine and neuroendocrine tumors but the role of inositol supplementation in this context has not been clarified. The aim of this review is to summarize the molecular basis of the possible role of inositols in endocrine and neuroendocrine tumors, proposing it as an adjuvant therapy.

TRAF6-mediated ubiquitination of AKT1 in the nucleus occurs in a β-arrestin2-dependent manner upon insulin stimulation

AKT, also known as protein kinase B (PKB), serves as a crucial regulator of numerous biological functions, including cell growth, metabolism, and tumorigenesis. Increasing evidence suggests that the kinase activity of AKT is regulated via ubiquitination by various E3 ligase enzymes in response to different stimuli. However, the molecular mechanisms underlying insulin-induced AKT ubiquitination are not yet fully understood. Here, we show that activation of the insulin receptor (IR) leads to enhanced ubiquitination of AKT1 at K8 and K14 residues, facilitated by the cytosolic E3 ubiquitin ligase enzyme, TRAF6. Further investigation using AKT1 mutants with modified nucleocytoplasmic shuttling properties reveals that TRAF6-mediated AKT1 ubiquitination occurs within the nucleus in a β-Arr2-dependent manner. The nuclear entry of TRAF6 depends on importin β1, while β-Arr2 regulates this process by facilitating the interaction between TRAF6 and importin β1. Additionally, the ubiquitination of AKT1 is essential for its translocation to the activated IR on the plasma membrane, where it plays a functional role in recruiting Glut4 and facilitating glucose uptake. This study uncovers the cellular components and processes involved in insulin-induced ubiquitination and activation of AKT1, providing insights and detailed strategies for manipulating AKT1.

Sex-Specific Expression of Histone Lysine Demethylases (KDMs) in Thyroid Cancer

BACKGROUND

The incidence of thyroid cancer in women is 3-4-fold higher than in men. To characterize sex-specific molecular alterations in thyroid cancer, we examined the expression of sex-biased genes in normal thyroids and thyroid tumors.

METHODS

Ingenuity pathways analysis was used to define sex-biased gene networks using data from the Cancer Genome Atlas (TCGA). Confirmatory studies were performed through the analysis of histone lysine demethylases (KDMs) expression by real-time PCR and immunostaining.

RESULTS

In normal thyroids, 44 sex-biased genes were comparatively upregulated in male and 28 in female patients. The expressions of 37/72 (51%) sex-biased genes were affected in cancer tissues compared with normal thyroids. Gene network analyses revealed sex-specific patterns in the expressions of KDM5C, KDM5D, and KDM6A. In confirmatory studies, KDM5D mRNA and protein were detected only in males, whereas KDM5C and KDM6A were detected in samples from male and female patients. Nuclear staining with anti-KDMs was found in normal thyroids, but a loss of nuclear expression with a concomitant gain of cytoplasmic staining was observed in cancer tissues.

CONCLUSIONS

Normal thyroids have a sex-specific molecular signature, and the development of thyroid cancer is associated with a differential expression of sex-biased genes. The sex-specific expression of KDMs, coupled with cancer-related alterations in their intracellular localization, may contribute to mechanisms underlying sex differences in thyroid tumorigenesis.

Role of Akt/Protein Kinase B in Cancer Metastasis

Metastasis is a critical step in the process of carcinogenesis and a vast majority of cancer-related mortalities result from metastatic disease that is resistant to current therapies. Cell migration and invasion are the first steps of the metastasis process, which mainly occurs by two important biological mechanisms, i.e., cytoskeletal remodelling and epithelial to mesenchymal transition (EMT). Akt (also known as protein kinase B) is a central signalling molecule of the PI3K-Akt signalling pathway. Aberrant activation of this pathway has been identified in a wide range of cancers. Several studies have revealed that Akt actively engages with the migratory process in motile cells, including metastatic cancer cells. The downstream signalling mechanism of Akt in cell migration depends upon the tumour type, sites, and intracellular localisation of activated Akt. In this review, we focus on the role of Akt in the regulation of two events that control cell migration and invasion in various cancers including head and neck squamous cell carcinoma (HNSCC) and the status of PI3K-Akt pathway inhibitors in clinical trials in metastatic cancers.

Utility of the Growth Differentiation Factor-15 in the Differential Diagnosis of Follicular-Patterned Lesions of the Thyroid on Cytopathologic and Histopathologic Samples

Background Follicular-patterned lesions are a major gray zone in thyroid cytopathology. The recently introduced 2022 World Health Organization (WHO) classification emphasizes the importance of genetic alterations in thyroid neoplasms with the introduction of certain newer terminologies that are expected to cause remarkable changes in cytopathologic and histopathologic reporting. Although molecular assays such as the Afirma gene expression classifier and the ThyroSeq are already in use, there has been an ongoing search for further reliable molecular markers. The growth differentiation factor-15 (GDF-15) is one among them. This study aimed to determine the diagnostic utility of GDF-15 mRNA expression in frozen tissue and fine-needle aspiration (FNA) samples from follicular-patterned thyroid lesions and neoplasms. Methodology The real-time quantitative polymerase chain reaction was performed on 75 frozen tissue and FNA samples each from 19 cases of follicular thyroid hyperplasia (FTH), 10 nodular goiters (NGs), 17 follicular thyroid adenomas (FTAs), eight follicular thyroid carcinomas (FTCs), 12 follicular variant of papillary thyroid carcinomas (FVPTCs), and nine classic papillary thyroid carcinomas (CPTCs) that were diagnosed according to the 2017 WHO classification of thyroid neoplasms. The GDF-15 mRNA expression in all these cases was assessed and compared with the control thyroid tissue samples. One-way analysis of variance and the Kruskal-Wallis test were performed using GraphPad Prism 8 software to determine the significance of differences in the GDF-15 mRNA levels among various thyroid lesions. Results A higher GDF-15 mRNA expression was noted in the malignant thyroid neoplasms including FTC, FVPTC, and CPTC in comparison to FTA, with a fold change between the malignant and benign groups being more than 244.18 times. A difference in the fold change was noted between FTH and FTA with an increase in GDF-15 mRNA level in the latter, which was statistically not significant. Conclusions The fact that GDF-15 mRNA was studied both on fine-needle aspiration cytologic and the frozen tissue material and that the majority of the lesions studied were follicular-patterned establishes the GDF-15 as a potential marker not only for diagnosing malignant thyroid neoplasms of the follicular epithelium but also in distinguishing benign and malignant follicular-patterned neoplasms of the thyroid.

STRA6 Promotes Thyroid Carcinoma Progression via Activation of the ILK/AKT/mTOR Axis in Cells and Female Nude Mice

BACKGROUND

Metastasis has emerged to be an important cause for poor prognosis of thyroid carcinoma (TC) and its molecular mechanisms are not fully understood. STRA6 is a multifunctional membrane protein widely expressed in embryonic and adult tissues. The function and mechanism of STRA6 in TC remain elusive.

OBJECTIVE

We aimed to explore the role of STRA6 in TC progression and provide a therapeutic target for TC.

METHODS

The expression and clinicopathological relevance of STRA6 were explored in TC. Stable STRA6-knockdown TC cells were established and used to determine the biological function of STRA6 in vitro and in vivo. RNA sequencing and co-immunoprecipitation were performed to unveil the molecular mechanism of STRA6 in TC progression. The potential of STRA6 as a therapeutic target was evaluated by lipid nanoparticles (LNPs) containing siRNA.

RESULTS

STRA6 was upregulated in TC and correlated with aggressive clinicopathological features, including extrathyroidal extension and lymph node metastasis, which contributed to the poor prognosis of TC. STRA6 facilitated TC progression by enhancing proliferation and metastasis in vitro and in vivo. Mechanistically, STRA6 could interact with integrin-linked kinase (ILK) and subsequently activate the protein kinase B/mechanistic target of rapamycin (AKT/mTOR) signaling pathway. We further unveiled that STRA6 reprogrammed lipid metabolism through SREBP1, which was crucial for the metastasis of TC. Moreover, STRA6 siRNA delivered by LNPs significantly inhibited cell growth in xenograft tumor models.

CONCLUSIONS

Our study demonstrates the critical roles of STRA6 contributing to TC progression via the ILK/AKT/mTOR axis, which may provide a novel prognostic marker as well as a promising therapeutic target for aggressive TC.

mTORC2 Is Activated under Hypoxia and Could Support Chronic Myeloid Leukemia Stem Cells

Hypoxia is a critical condition that governs survival, self-renewal, quiescence, metabolic shift and refractoriness to leukemic stem cell (LSC) therapy. The present study aims to investigate the hypoxia-driven regulation of the mammalian Target of the Rapamycin-2 (mTORC2) complex to unravel it as a novel potential target in chronic myeloid leukemia (CML) therapeutic strategies. After inducing hypoxia in a CML cell line model, we investigated the activities of mTORC1 and mTORC2. Surprisingly, we detected a significant activation of mTORC2 at the expense of mTORC1, accompanied by the nuclear localization of the main substrate phospho-Akt (Ser473). Moreover, the Gene Ontology analysis of CML patients' CD34+ cells showed enrichment in the mTORC2 signature, further strengthening our data. The deregulation of mTOR complexes highlights how hypoxia could be crucial in CML development. In conclusion, we propose a mechanism by which CML cells residing under a low-oxygen tension, i.e., in the leukemia quiescent LSCs, singularly regulate the mTORC2 and its downstream effectors.

Inhibition of secretory leukocyte protease inhibitor (SLPI) promotes the PUMA-mediated apoptosis and chemosensitivity to cisplatin in colorectal cancer cells

BACKGROUND

Aberrant expression of Secretory Leukocyte Protease Inhibitor (SLPI) has been associated with human cancer growth and its suppression was identified as a potential target for anti-cancer drugs, particularly in colorectal cancer. However, the underlying mechanism by which SLPI affected the development of drug resistance in CRC remains unclear.

OBJECTIVE

This study investigated the role of SLPI in the p53-up-regulated modulator of apoptosis (PUMA)-mediated CRC cells' apoptosis and their chemosensitivity to Cisplatin.

METHODS

A series of qRT-PCR and western blot analyses were performed to characterize the expressions of SLPI, PUMA, and Akt in CRC lines. Tunel, transwell, and CCK-8 analyses were monitored to define the impacts of the siRNA-mediated knockdown of SLPI on CRC cell development. Furthermore, in vivo development of CRC was evaluated in nude mice infected with siSLPI or Cisplatin alone or both, and Ki67 and caspase-3 immunohistochemistry assay was monitored on multiple tissue microarray from the same cohort.

RESULTS

Our results showed that SLPI inhibition strongly promoted the expressions of the pro-apoptotic protein PUMA, cleaved-caspase3 and Bax and reduced the cell viability of HT29 and HT116 cell lines in vitro. In addition, siSLPI knockdown effectively suppressed both Akt and FoxO3 proteins and improved the sensitivity to cisplatin chemotherapy. Xenograft tumor assay revealed a lowered growth in mice treated with Cisplatin, while combined treatment of siSLPI achieved more significant anticancer effects than Cisplatin alone.

CONCLUSIONS

Taken together, these findings demonstrated that suppression of SLPI might repress the growth of human colorectal cancer cells both in vitro and in vivo. These results suggested SLPI as a novel resistance factor to Cisplatin, and a combination of Cisplatin and SLPI inhibitor be beneficial for colorectal cancer therapy.

Decrypting a path based approach for identifying the interplay between PI3K and GSK3 signaling cascade from the perspective of cancer

Cancer is one of those leading diseases worldwide, which takes millions of lives every year. Researchers are continuously looking for specific approaches to eradicate the deadly disease, ensuring minimal adverse effects along with more therapeutic significance. Targeting of different aberrantly regulated signaling pathways, involved in cancer, is surely one of the revolutionary chemotherapeutic approach. In this instance, GSK3 and PI3K signaling cascades are considered as important role player for both the oncogenic activation and inactivation which further leads to cancer proliferation and metastasis. In this review, we have discussed the potential role of GSK3 and PI3K signaling in cancer, and we further established the crosstalk between PI3K and GSK3 signaling, through showcasing their cross activation, cross inhibition and convergence pathways in association with cancer. We also exhibited the effect of GSK3 on the efficacy of PI3K inhibitors to overcome the drug resistance and preventing the cell proliferation, metastasis in a combinatorial way with GSK3 inhibitors for a better treatment strategy in clinical settings.

Study on endocrine disruption effect of paclobutrazol and uniconazole on the thyroid of male and female rats based on lipidomics

The present study investigated the effects of paclobutrazol and uniconazole on thyroid endocrine system in rats. Lipidomic analysis was performed to obtain the biomarkers of thyroid endocrine disruption induced by paclobutrazol and uniconazole. Network pharmacology was further used to discover potential targets of biomarkers related to drugs and diseases. After paclobutrazol and uniconazole administration, seven and four common biomarkers related to thyroid endocrine disruption for female and male rats were obtained, respectively. Paclobutrazol and uniconazole significantly increased the biomarker levels of PG (12:0/15:0), PS (14:0/16:0), PA (20:1/15:0) and PG (13:0/17:0) in both sexes of rats. Exposure to paclobutrazol additionally caused a significant decrease of PG (22:6/20:2), PE (24:1/18:1) and PE (24:0/18:0) in female rats, while an increase in male rats. Changes of the common biomarkers for paclobutrazol and uniconazole revealed similar endocrine disruption effect, which was higher in the females. Network pharmacology and KEGG pathway analysis indicated that the thyroid endocrine disrupting effects of paclobutrazol and uniconazole may be related to V-akt murine thymoma viral oncogene homolog (Akts), mitogen-activated protein kinase (MAPKs), epidermal growth factor receptor (EGFR), Insulin-like growth factor (IGF-1), IGF-IR and V-Raf murine sarcoma viral oncogene homolog B1 (BRAF). The results demonstrated that paclobutrazol and uniconazole could cause thyroid endocrine disorders in male and female rats, which were sex-specific, thus highlighting the importance of safe and effective application of these plant growth regulators.

Aagab acts as a novel regulator of NEDD4-1-mediated Pten nuclear translocation to promote neurological recovery following hypoxic-ischemic brain damage

Hypoxic-ischemic encephalopathy (HIE) is a main cause of mortality and severe neurologic impairment in the perinatal and neonatal period. However, few satisfactory therapeutic strategies are available. Here, we reported that a rapid nuclear translocation of phosphatase and tensin homolog deleted on chromosome TEN (PTEN) is an essential step in hypoxic-ischemic brain damage (HIBD)- and oxygen-glucose deprivation (OGD)-induced neuronal injures both in vivo and in vitro. In addition, we found that OGD-induced nuclear translocation of PTEN is dependent on PTEN mono-ubiquitination at the lysine 13 residue (K13) that is mediated by neural precursor cell expressed developmentally downregulated protein 4-1 (NEDD4-1). Importantly, we for the first time identified α- and γ-adaptin binding protein (Aagab) as a novel NEDD4-1 regulator to regulate the level of NEDD4-1, subsequently mediating Pten nuclear translocation. Finally, we demonstrated that genetic upregulation of Aagab or application of Tat-K13 peptide (a short interference peptide that flanks K13 residue of PTEN) not only reduced Pten nuclear translocation, but also significantly alleviated the deficits of myodynamia, motor and spatial learning and memory in HIBD model rats. These results suggest that Aagab may serve as a regulator of NEDD4-1-mediated Pten nuclear translocation to promote functional recovery following HIBD in neonatal rats, and provide a new potential therapeutic target to guide the clinical treatment for HIE.

Targeting EML4-ALK gene fusion variant 3 in thyroid cancer

Finding targetable gene fusions can expand the limited treatment options in radioactive iodine-refractory (RAI-r) thyroid cancer. To that end, we established a novel cell line 'JVE404' derived from an advanced RAI-r papillary thyroid cancer (PTC) patient, harboring an EML4-ALK gene fusion variant 3 (v3). Different EML4-ALK gene fusions can have different clinical repercussions. JVE404 cells were evaluated for cell viability and cell signaling in response to ALK inhibitors crizotinib, ceritinib and lorlatinib, in parallel to the patient's treatment. He received, after first-line lenvatinib, crizotinib (Drug Rediscovery Protocol (DRUP) trial), and lorlatinib (compassionate use). In vitro treatment with crizotinib or ceritinib decreased viability in JVE404, but most potently and significantly only with lorlatinib. Western blot analysis showed a near total decrease of 99% and 89%, respectively, in pALK and pERK expression levels in JVE404 cells with lorlatinib, in contrast to remaining signal intensities of a half and a third of control, respectively, with crizotinib. The patient had a 6-month lasting stable disease on crizotinib, but progressive disease occurred, including the finding of cerebral metastases, at 8 months. With lorlatinib, partial response, including clinical cerebral activity, was already achieved at 11 weeks' use and ongoing partial response at 7 months. To our best knowledge, this is the first reported case describing a patient-specific targeted treatment with lorlatinib based on an EML4-ALK gene fusion v3 in a thyroid cancer patient, and own cancer cell line. Tumor-agnostic targeted therapy may provide valuable treatment options in personalized medicine.

Thidiazuron decreases epithelial-mesenchymal transition activity through the NF-kB and PI3K/AKT signalling pathways in breast cancer

Breast cancer is the major type among the women population globally. The treatment of cancer metastasis has made modest progress due to multiple factors. Thidiazuron (TDZ) is a novel plant growth regulator that has been shown to have anticancer effects. Therefore, we explored the anti-metastatic potentials of TDZ in cell lines by assessing its potential to suppress the epithelial-mesenchymal transition (EMT). We pretreated the BEAS-2B and breast cancer (MDA-MB-231) cells with TDZ and deliberated alteration in a cell viability, mammosphere, migration, NF-кB signalling, PI3K/AKT signalling and matrix metalloproteinase (MMP) expression and analysed the EMT induction by TGF-β/TNF-α-stimulated BEAS-2B cells. Treatment with TDZ (5-50 μmol) diminished the migration and invasion of the extremely metastatic MDA-MB-231 cells. Additionally, TDZ treatment led to down-regulation of uPAR, uPA, VEGF and MMP-2/-9 expression and up-regulation of TIMP-1/2 expression in these cells. Furthermore, TDZ treatment blocked invasion and EMT in non-tumorigenic BEAS-2B epithelial cells stimulated with TGF-β/TNF-α.TDZ prevents EMT and may thus block metastasis of breast cancer cells.

Exploring Dysregulated Signaling Pathways in Cancer

Cancer cell biology takes advantage of identifying diverse cellular signaling pathways that are disrupted in cancer. Signaling pathways are an important means of communication from the exterior of cell to intracellular mediators, as well as intracellular interactions that govern diverse cellular processes. Oncogenic mutations or abnormal expression of signaling components disrupt the regulatory networks that govern cell function, thus enabling tumor cells to undergo dysregulated mitogenesis, to resist apoptosis, and to promote invasion to neighboring tissues. Unraveling of dysregulated signaling pathways may advance the understanding of tumor pathophysiology and lead to the improvement of targeted tumor therapy. In this review article, different signaling pathways and how their dysregulation contributes to the development of tumors have been discussed.

Akt isoform-specific effects on thyroid cancer development and progression in a murine thyroid cancer model

The Akt family is comprised of three unique homologous proteins with isoform-specific effects, but isoform-specific in vivo data are limited in follicular thyroid cancer (FTC), a PI3 kinase-driven tumor. Prior studies demonstrated that PI3K/Akt signaling is important in thyroid hormone receptor βPV/PV knock-in (PV) mice that develop metastatic thyroid cancer that most closely resembles FTC. To determine the roles of Akt isoforms in this model we crossed Akt1-/-, Akt2-/-, and Akt3-/- mice with PV mice. Over 12 months, thyroid size was reduced for the Akt null crosses (p < 0.001). Thyroid cancer development and local invasion were delayed in only the PVPV-Akt1 knock out (KO) mice in association with increased apoptosis with no change in proliferation. Primary-cultured PVPV-Akt1KO thyrocytes uniquely displayed a reduced cell motility. In contrast, loss of any Akt isoform reduced lung metastasis while vascular invasion was reduced with Akt1 or 3 loss. Microarray of thyroid RNA displayed incomplete overlap between the Akt KO models. The most upregulated gene was the dendritic cell (DC) marker CD209a only in PVPV-Akt1KO thyroids. Immunohistochemistry demonstrated an increase in CD209a-expressing cells in the PVPV-Akt1KO thyroids. In summary, Akt isoforms exhibit common and differential functions that regulate local and metastatic progression in this model of thyroid cancer.

Knockdown of TRPM7 prevents tumor growth, migration, and invasion through the Src, Akt, and JNK pathway in bladder cancer

Background

Bladder cancer (BC) is one of the most common malignancies of the urinary tract. The role of transient receptor potential melastatin 7 (TRPM7) in BC remains unclear. The aim of this study was to investigate the function and signal transduction pathway of TRPM7 in BC.

Methods

T24 and UMUC3 cells were used to evaluate the molecular mechanism of TRPM7 by immunoblot analysis. Small interfering RNA was used to knockdown TRPM7, and the effect of silencing TRPM7 was studied by wound healing, migration, and invasion assays in T24 and UMUC3 cells. Xenograft model study was obtained to analyze the effect of TRPM7 inhibition in vivo.

Results

Silencing of TRPM7 decreased the migration and invasion ability of T24 and UMUC3 cells. The phosphorylation of Src, Akt, and JNK (c-Jun N-terminal kinase) was also suppressed by TRPM7 silencing. Src, Akt, and JNK inhibitors effectively inhibited the migration and invasion of T24 and UMUC3 cells. In addition, the TRPM7 inhibitor, carvacrol, limited the tumor size in a xenograft model.

Conclusion

Our data reveal that TRPM7 regulates the migration and invasion of T24 and UMUC3 cells via the Src, Akt, and JNK signaling pathway. Therefore, TRPM7 suppression could be a potential treatment for BC patients.

Nuclear actin in cancer biology

The presence of actin in the nucleus has been a matter of debate for many years. In recent years many important roles of actin in the nucleus (transcriptional regulation, chromatin remodeling, DNA repair, cell division, maintenance of nuclear architecture) have been identified, and the precise control of nuclear actin levels has been demonstrated. The vital importance of the actin driven processes in the cell make it highly likely that dysregulation of nuclear actin dynamics and structure can be linked to tumor induction and -progression. In this chapter I summarize our current knowledge about nuclear actin in the cancer context.

Resveratrol potentiates the anti-tumor effects of rapamycin in papillary thyroid cancer: PI3K/AKT/mTOR pathway involved

The phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway plays an important role in the development of papillary thyroid cancer. While rapamycin has been shown to exhibit anti-tumor effects, it may also activate AKT, resulting in increased cell survival and drug resistance, thereby limiting its anti-tumor effects. Resveratrol can also inhibit tumor growth by regulating the PI3K/AKT/mTOR signaling pathway. The present study investigated the anti-tumor effects of the combined use of rapamycin and resveratrol in papillary thyroid cancer. We first treated two human papillary thyroid cancer cell lines (KTC-1 and TPC-1) with single or combined administration, and examined the effects on proliferation, the cell cycle, apoptosis, and invasion/migration of papillary thyroid cancer cells. A mouse xenograft model was induced with KTC-1 and TPC-1 cells followed by treatment with single or combined administration. Body weight and tumor size were monitored to assess the toxicity of each compound. The phosphorylation of AKT and the mTORC1 target p70S6 kinase (p70S6K) in tumors was also examined. Both rapamycin and resveratrol inhibited proliferation, altered the cell cycle, and induced apoptosis of papillary thyroid cancer cells. Invasion and migration were also reduced, as was the tumor growth rate in the xenograft model. Co-administration significantly enhanced the anti-tumor effects than use of any one drug, and significantly reduced the phosphorylation of AKT and p70S6K compared to treatment with rapamycin alone. Overall, compared to single use of rapamycin or resveratrol, co-administration had a synergistic effect in inhibiting proliferation and invasion/migration of papillary thyroid cancer cells and inducing apoptosis. Resveratrol is sensitizing the anti-tumor effects of rapamycin and the PI3K/AKT/mTOR signaling is involved. Although further animal and clinical studies are needed to clarify the mechanism and assess drug safety, the present study suggests that the combination of rapamycin and resveratrol may be a promising strategy for the treatment of papillary thyroid cancer.

Cancer Stem Cells in Thyroid Tumors: From the Origin to Metastasis

Thyroid tumors are extremely heterogeneous varying from almost benign tumors with good prognosis as papillary or follicular tumors, to the undifferentiated ones with severe prognosis. Recently, several models of thyroid carcinogenesis have been described, mostly hypothesizing a major role of the thyroid cancer stem cell (TCSC) population in both cancer initiation and metastasis formation. However, the cellular origin of TCSC is still incompletely understood. Here, we review the principal epigenetic mechanisms relevant to TCSC origin and maintenance in both well-differentiated and anaplastic thyroid tumors. Specifically, we describe the alterations in DNA methylation, histone modifiers, and microRNAs (miRNAs) involved in TCSC survival, focusing on the potential of targeting aberrant epigenetic modifications for developing novel therapeutic approaches. Moreover, we discuss the bidirectional relationship between TCSCs and immune cells. The cells of innate and adaptive response can promote the TCSC-driven tumorigenesis, and conversely, TCSCs may favor the expansion of immune cells with protumorigenic functions. Finally, we evaluate the role of the tumor microenvironment and the complex cross-talk of chemokines, hormones, and cytokines in regulating thyroid tumor initiation, progression, and therapy refractoriness. The re-education of the stromal cells can be an effective strategy to fight thyroid cancer. Dissecting the genetic and epigenetic landscape of TCSCs and their interactions with tumor microenvironment cells is urgently needed to select more appropriate treatment and improve the outcome of patients affected by advanced differentiated and undifferentiated thyroid cancers.

Vemurafenib may overcome TNF-related apoptosis-inducing ligand (TRAIL) resistance in anaplastic thyroid cancer cells

PURPOSE

Anaplastic thyroid cancer (ATC) is rare but with poor prognosis. TRAIL can selectively induce apoptosis in cancer cells; however, resistance is quite common. Aim of our study was to evaluate TRAIL-induced apoptosis in ATC-derived cell lines, in vitro and in vivo, and the effect of combination with tyrosine kinase inhibitors (TKIs) selective for BRAF (vemurafenib) or Akt (MK-2206).

METHODS

Four ATC-derived cell lines were used: C643, CAL62, HTh7, with activating mutation of RAS and copy gain of PI3K (HTh7) and, 8505C with activating mutation of BRAF. Cells were treated with TRAIL alone or in combination with vemurafenib or MK-2206. The pro-apoptotic effect of TRAIL alone or combined with TKIs was, also, evaluated in two mouse xenograft models (HTh7 and 8505C).

RESULTS

C643, CAL62, and HTh7 cells were sensitive to TRAIL-induced apoptosis, whereas 8505C cells were resistant. Both in vitro and in vivo vemurafenib was able to increase the TRAIL-induced apoptosis in 8505C cells causing a slower tumor growth in 8505C xenograft compared to placebo, while MK-2206 did not have any additive effect on TRAIL treatment in HTh7 model.

CONCLUSIONS

TRAIL is a promising therapeutic agent in ATC and in case of resistance vemurafenib may be a valid complementary therapy.

The relation between PI3K/AKT signalling pathway and cancer

Phosphatidylinositol 3-kinases (PI3Ks) are crucial coordinators of intracellular signalling in response to the extracellular stimulators. Hyperactivation of PI3K signalling cascades is one among the most ordinary events in human cancers. Focusing on the PI3K pathway remains both a chance and a challenge for cancer therapy. The high recurrence of phosphoinositide 3-kinase (PI3K) pathway adjustments in cancer has led to a surge in the progression of PI3K inhibitors. Recent developments incorporate a re-assessment of the oncogenic mechanisms behind PI3K pathway modifications. Receptor tyrosine kinases upstream of PI3K, the p110a catalytic fractional unit of PI3K, the downstream kinase, AKT, and therefore the negative regulator, PTEN, are all often altered in cancer. In this review, we consider about the phosphoinositide 3-kinases family and mechanisms of PI3K-Akt stimulation in cancer.

Coding Molecular Determinants of Thyroid Cancer Development and Progression

Thyroid cancer is the most common endocrine malignancy. Its incidence and mortality rates have increased for patients with advanced-stage papillary thyroid cancer. The characterization of the molecular pathways essential in thyroid cancer initiation and progression has made huge progress, underlining the role of intracellular signaling to promote clonal evolution, dedifferentiation, metastasis, and drug resistance. The discovery of genetic alterations that include mutations (BRAF, hTERT), translocations, deletions (eg, 9p), and copy-number gain (eg, 1q) has provided new biological insights with clinical applications. Understanding how molecular pathways interplay is one of the key strategies to develop new therapeutic treatments and improve prognosis.

Effect of insulin on thyroid cell proliferation, tumor cell migration, and potentially related mechanisms

BACKGROUND

Diabetes has recently been identified as a risk factor for a variety of cancers, possibly due to hyperinsulinemia or exogenous insulin use. Thyroid cancer is the most common endocrine malignancy, and its incidence has been exponentially increasing worldwide at an alarming rate. The aim of this study was to establish whether insulin use affects thyroid cancer development and progression, specifically cell proliferation and migration in vitro.

METHODS

In this study, we investigated the effects of the insulin agents most commonly used in the clinic, regular human insulin (HI) and insulin glargine (IG), on the proliferation and migration of thyroid cells.

RESULTS

Both HI and IG affected the thyroid cells in a dose-dependent manner and at high concentrations significantly promoted thyroid cell proliferation and tumor cell migration. The promoting effect might be elicited by activation of the insulin receptor and insulin-like growth factor-1 receptor and through the downstream Akt-signaling pathway, which inhibits the activity of the tumor-suppressor FoxO3a. In particular, MAPK-signaling cascades were activated in papillary thyroid carcinoma cell-1 cells but not in follicular rat thyroid-5 cells.

CONCLUSION

The in vitro evidence demonstrated that HI and IG can promote thyroid cell proliferation and tumor cell migration at supraphysiological concentrations, but the effect was not significant at low concentrations. Whether high-dose insulins could affect diabetic patients with thyroid cancer or undetected (pre)cancerous lesions needs further in vivo study.

ABBREVIATIONS

HI: human regular insulin; IG: insulin glargine; IR: insulin receptor; IGF-1R: insulin-like growth factor-1 receptor; Akt: protein kinase B (PKB); MAPK: mitogen-activated protein kinase; FoxO3a: the forkhead box-containing protein: class O 3a.

AKT/protein kinase B associates with β-actin in the nucleus of melanoma cells

The serine-threonine kinase AKT/PKB is a critical regulator of various essential cellular processes, and dysregulation of AKT has been implicated in many diseases, including cancer. Despite AKT action is known to function mainly in the cytoplasm, AKT has been reported to translocate to the nucleus. However, very little is known about the mechanism required for the nuclear import of AKT as well as its function in this cellular compartment. In the present study, we characterized the presence of endogenous nuclear AKT in human melanoma cells and addressed the possible role of AKT by exploring its potential association with key interaction nuclear partners. Confocal and Western blot analyses showed that both phosphorylated and non-phosphorylated forms of AKT are present in melanoma cells nuclei. Using mass spectrometry in combination with protein-crosslinking and co-immunoprecipitation, we identified a series of putative protein partners of nuclear AKT, including heterogeneous nuclear ribonucleoprotein (hnRNP), cytoskeleton proteins β-actin, γ-actin, β-actin-like 2 and vimentin. Confocal microscopy and biochemical analyses validated β-actin as a new nuclear AKT-interacting partner. Cofilin and active RNA Polymerase II, two proteins that have been described to interact and work in concert with nuclear actin in transcription regulation, were also found associated with nuclear AKT. Overall, the present study uncovered a yet unrecognized nuclear coupling of AKT and provides insights into the involvement of AKT in the interaction network of nuclear actin.

A molecular approach combined with American Thyroid Association classification better stratifies recurrence risk of classic histology papillary thyroid cancer

BACKGROUND

Prognosis among patients with differentiated thyroid cancer is widely variable. Better understanding of biologic subtypes is necessary to stratify patients and improve outcomes.

METHODS

In patients diagnosed with classic histology papillary thyroid cancer treated from 1973 to 2009, BRAF V600E mutation status was determined on surgical tumor specimens by restriction fragment length polymorphism analysis. A tissue microarray (TMA) was constructed from tumor specimens in triplicate and stained by immunohistochemistry for RET, phospho-MEK, MAPK(dpERK), PPARγ, and phospho-AKT(pAKT). Stained slides were scored independently and blindly by two investigators and compared to tumor and patient characteristics and outcomes.

RESULTS

A total of 231 patients had archived formalin-fixed, paraffin-embedded tumor tissue available and were included on the TMA. Mean age at diagnosis was 44 years (range 6-82 years); proportion of patients with female sex was (72%); 2015 American Thyroid Association (ATA) risk stratification was low (26%), intermediate (32%), and high (42%). BRAF V600E mutation was found in 74% of specimens, and IHC was scored as positive for RET (61%), MAPK (dpERK) (14%), PPARγ (27%), and pAKT (39%). Positive RET staining was associated with a lower risk of recurrence (HR = 0.46, 95% CI 0.22-0.96). No other molecular biomarkers were independent predictors of recurrence on univariable analysis. On RPA, patients with RET-negative and either MAPK(dpERK)-positive or pAKT-positive tumors were identified to have a high risk of recurrence (HR = 5.4, 95%CI 2.5-11.7). This profile remained associated with recurrence in a multivariable model including ATA risk stratification (HR = 2.8, 95% CI 1.3-6.0).

CONCLUSION

Characterization of molecular pathways involved in cPTC tumorigenesis may add further risk stratification for recurrence beyond the 2015 ATA risk categories alone.

MKRN2 inhibits migration and invasion of non-small-cell lung cancer by negatively regulating the PI3K/Akt pathway

Background

Makorin RING zinc finger-2 (MKRN2) belongs to the makorin RING zinc finger family and is a novel ubiquitin E3 ligase targeting the p65 subunit of NF-κB to negatively regulate inflammatory responses; however, the relationship between MKRN2 and tumorigenesis remains unclear. In this study, we clarified the role of MKRN2 in non-small cell lung cancer (NSCLC).

Methods

Tumor specimens collected from 261 NSCLC patients from 2013 to 2017 were retrieved from the Pathology Archive of the First Affiliated Hospital of China Medical University, and we performed assays to evaluate MKRN2 expression and to determine the impact of MKRN2 silencing and overexpression on NSCLC-cell migration and invasion.

Results

We demonstrated that MKRN2 expression was associated with lymph node metastasis, p-TNM stage, cancer-cell differentiation, and poor prognosis. By altering the expression of MKRN2 in selected cell lines, we found that MKRN2 inhibited cell migration and invasion through downregulation of the PI3K/Akt pathway.

Conclusions

These results suggested that MKRN2 inhibited NSCLC progression by reducing the metastatic potential of cancer cells. Our findings provide critical insight into the association of MKRN2 expression with favorable clinicopathological characteristics in NSCLC patients and suggested that MKRN2 plays a role in inhibiting NSCLC development.

Prognostic significance of cyclooxygenase 2 and phosphorylated Akt1 overexpression in primary nonmetastatic and metastatic cutaneous melanomas

Cyclooxygenase 2 (COX-2) and phosphorylated Akt1 (p-Akt1) are associated with tumor spreading, cell proliferation, high metabolism, and angiogenesis in solid tumors. This study aimed to investigate COX-2 and p-Akt1 expression in primary and metastatic melanomas by correlating with the cellular proliferation index (as revealed by minichromosome maintenance 2 expression) and the outcome of patients with malignant melanomas. Seventy-seven biopsies of malignant melanomas, including 42 primary nonmetastatic melanomas (PNMMs), 12 primary metastatic melanomas (PMMs), and 23 metastatic melanomas (MMs), were retrospectively selected. Tissue microarrays were developed and submitted for immunohistochemical staining for COX-2, p-Akt1, and minichromosome maintenance 2. Increased COX-2 cytoplasmic staining patterns were observed in PMM and MM when compared with PNMM (P=0.0011). Higher nuclear and cytoplasmic expression of p-Akt1 was more closely associated with PMM than with MM and PNMM (P<0.00001). Coexpression of these biomarkers was closely correlated with lower overall survival rates in melanomas. Furthermore, we observed a statistically significant positive correlation between the mitosis index and increased COX-2 expression (P=0.0135) and between p-Akt1 (P=0.0038) and the cellular proliferation index (P=0.0060). Taken together, our findings demonstrate that COX-2 and p-Akt1 play an important combined role during melanoma progression and are associated with highly metastatic tumors and survival rates in patients with MM. In addition, these biomarkers can be used to predict melanoma prognosis independently of metastatic status. However, further studies are required to elucidate the biological role of these biomarkers during the progression of MM events.

mTOR Pathway in Papillary Thyroid Carcinoma: Different Contributions of mTORC1 and mTORC2 Complexes for Tumor Behavior and SLC5A5 mRNA Expression

The mammalian target of rapamycin (mTOR) pathway is overactivated in thyroid cancer (TC). We previously demonstrated that phospho-mTOR expression is associated with tumor aggressiveness, therapy resistance, and lower mRNA expression of SLC5A5 in papillary thyroid carcinoma (PTC), while phospho-S6 (mTORC1 effector) expression was associated with less aggressive clinicopathological features. The distinct behavior of the two markers led us to hypothesize that mTOR activation may be contributing to a preferential activation of the mTORC2 complex. To approach this question, we performed immunohistochemistry for phospho-AKT Ser473 (mTORC2 effector) in a series of 182 PTCs previously characterized for phospho-mTOR and phospho-S6 expression. We evaluated the impact of each mTOR complex on SLC5A5 mRNA expression by treating cell lines with RAD001 (mTORC1 blocker) and Torin2 (mTORC1 and mTORC2 blocker). Phospho-AKT Ser473 expression was positively correlated with phospho-mTOR expression. Nuclear expression of phospho-AKT Ser473 was significantly associated with the presence of distant metastases. Treatment of cell lines with RAD001 did not increase SLC5A5 mRNA levels, whereas Torin2 caused a ~6 fold increase in SLC5A5 mRNA expression in the TPC1 cell line. In PTC, phospho-mTOR activation may lead to the activation of the mTORC2 complex. Its downstream effector, phospho-AKT Ser473, may be implicated in distant metastization, therapy resistance, and downregulation of SLC5A5 mRNA expression.

Acquired resistance to BRAF inhibition induces epithelial-to-mesenchymal transition in BRAF (V600E) mutant thyroid cancer by c-Met-mediated AKT activation

Previously, the authors have identified that c-Met mediates reactivation of the PI3K/AKT pathway following BRAF inhibitor treatment in BRAF (V600E) mutant anaplastic thyroid cancer, thereby contributing to the acquired drug resistance. Therefore dual inhibition of BRAF and c-Met led to sustained treatment response, thereby maximizing the specific anti-tumor effect of targeted therapy. The present study goes one step further and aims to investigate the effect of acquired resistance of BRAF inhibitor on epithelial-to-mesenchymal transition (EMT) in BRAF mutant thyroid cancer cells and the effect of dual inhibition from combinatorial therapy. Two thyroid cancer cell lines, 8505C and BCPAP were selected and treated with BRAF inhibitor, PLX4032 and its effect on EMT were examined and compared. Further investigation was carried out in orthotopic xenograft mouse models. Unlike BCPAP cells, the BRAF inhibitor resistant 8505C cells showed increased expressions of EMT related markers such as vimentin, β-catenin, and CD44. The combinatorial treatment of PLX4032 and PHA665752, a c-Met inhibitor reversed EMT. Similar results were confirmed in vivo. c-Met-mediated reactivation of the PI3K/AKT pathway contributes to the drug resistance to PLX4032 in BRAF (V600E) mutant anaplastic thyroid cancer cells and further promotes tumor cell migration and invasion by upregulated EMT mechanism. Dual inhibition of BRAF and c-Met leads to reversal of EMT, suggesting a maximal therapeutic response.

Phosphatidyl inositol-3 kinase (PIK3CA) E545K mutation confers cisplatin resistance and a migratory phenotype in cervical cancer cells

The phosphatidylinositol-3 kinase (PI3K)/Akt/mTOR signaling pathway is activated in many human cancers. Previously, we reported that patients with early stage cervical cancer whose tumours harbour PIK3CA exon 9 or 20 mutations have worse overall survival in response to treatment with radiation and cisplatin than patients with wild-type PIK3CA. The purpose of this study was to determine whether PIK3CA-E545K mutation renders cervical cancer cells more resistant to cisplatin and/or radiation, and whether PI3K inhibition reverses the phenotype. We found that CaSki cells that are heterozygous for the PIK3CA-E545K mutation are more resistant to cisplatin or cisplatin plus radiation than either HeLa or SiHa cells that express only wild-type PIK3CA. Similarly, HeLa cells engineered to stably express PIK3CA-E545K were more resistant to cisplatin or cisplatin plus radiation than cells expressing only wild-type PIK3CA or with PIK3CA depleted. Cells expressing the PIK3CA-E545K mutation also had constitutive PI3K pathway activation and increased cellular migration and each of these phenotypes was reversed by treatment with the PI3K inhibitor GDC-0941/Pictilisib. Our results suggests that cervical cancer patients whose tumours are positive for the PIK3CA-E545K mutation may benefit from PI3K inhibitor therapy in concert with standard cisplatin and radiation therapy.

Interleukin-33 enhanced the migration and invasiveness of human lung cancer cells

Aim

Interleukin-33 (IL-33), belonging to IL-1 family cytokines, has been reported to participate in cancer growth and metastasis. The clinical values of IL-33 in lung cancer have been previously investigated. We aimed to elucidate the probable role of IL-33 in the migration and invasion of lung cancer cells.

Methods

Cell migration and invasiveness were tested by Transwell assay. Western blotting analysis was performed to detect protein expression.

Results

We found that IL-33 treatment in human lung A549 cells dose-dependently enhanced their migratory and invasive ability, accompanied by elevated expression of matrix metallo-proteinase (MMP) 2 and MMP9. Meanwhile, IL-33-induced cell migration and invasion were significantly abolished by small interfering RNA-targeting ST2, the specific receptor of IL-33. Furthermore, IL-33 exposure induced the phosphorylation of AKT. Pretreatment with an AKT inhibitor LY294002 markedly attenuated IL-33-induced cell migration and invasion.

Conclusion

IL-33/ST2 promoted the migration and invasiveness of lung cancer cells through AKT pathway. Our findings strongly suggest that IL-33 may serve as a promising therapeutic strategy for lung cancer.

Identification of a novel HRAS variant and its association with papillary thyroid carcinoma

HRas proto-oncogene (HRAS) is one of the most commonly mutated genes in thyroid cancer, with mutations frequently occurring in the follicular and Hurthle cell subtypes. However, the contribution of mutations in HRAS to papillary thyroid carcinoma (PTC) progression and the tall-cell variant (TCV) is poorly understood. The aim of the present study was to investigate the somatic genetic variants present in HRAS in patients with PTC, and to investigate the association of these mutations with PTC. The present study is a retrospective case-control study using tumor samples collected from 139 patients with PTC and blood samples from 195 healthy individuals. All patient samples were screened for mutations in 'hotspot' regions of HRAS and B-raf proto-oncogene (BRAF) by single-stranded conformational polymorphism analysis, followed by direct sequencing. A novel variant (IVS1-82del gctgggcctggg) in the HRAS 5'-untranslated region was identified. There was no difference in age or sex of patients with PTC and the healthy controls; however, the HRAS variant was more frequently detected in PTC tissue than in the healthy control samples (37 vs. 26%, P=0.04). There was no association between the HRAS variant and age, sex, tumor size, encapsulation, multifocality/intra-thyroidal spread, Tumor-Node-Metastasis stage, history of Hashimoto's disease, BRAF V600E mutation or PTC subtype (all P>0.05). There were differences of BRAF V600E distribution among different subtypes (χ²=6.390, P=0.041). HRAS variant co-occurring with the BRAF V600E mutation accounted for 31.6% of the total number (P=0.196). Therefore, this novel variant of HRAS (IVS1-82del gctgggcctggg) may be associated with PTC; however, larger scale studies are required to assess the contribution of this novel HRAS variant to PTC progression.

Isolation and identification of tumor-initiating cell properties in human gallbladder cancer cell lines using the marker cluster of differentiation 133

The present study aimed to isolate and identify the properties of the cluster of differentiation (CD)133+ subset in human gallbladder cancer cells. The CD133+ and CD133- subpopulations of the GBC-SD cell line were separated using immunomagnetic separation, and the biological features of the two subpopulations were analyzed in vitro and in vivo. In particular, the present study aimed to determine whether the two subpopulations were resistant to anti-tumor reagents and to identify the underlying molecular mechanisms involved. Following cell sorting of GBC-SD cells using immunomagnetic beads, 90.2±2% of cells were identified as CD133+. Immunofluorescence confirmed that CD133 was expressed at higher levels in the Cd133+ group compared with the CD133- group. The proliferation of the CD133+ group was significantly increased compared with the CD133- group in vitro and in vivo. Following treatment with fluorouracil or gemcitabine, cells in the CD133+ group exhibited a decreased sensitivity to these drugs. The number of transmembrane cells was significantly increased in the CD133+ group compared with the CD133- group. In addition, the expression levels of ATP binding cassette subfamily G member 2, CD44, C-X-C motif chemokine receptor 4 (CXCR4), phosphorylated-protein kinase B (Akt) and CD133 in the CD133+ group were significantly increased, compared with those in the CD133- group. In CD133+ GBC-SD cells, stromal cell-derived factor 1α (SDF-1α) or treatment with AMD3100, an inhibitor of CXCR4, promotes or suppresses the SDF-1α/CXCR4 axis, respectively, resulting in increased or decreased CD133 expression through the Akt signaling pathway. Inhibition of the Akt signaling pathway resulted in decreased CD133 expression in GBC-SD cells. Immunomagnetic beads were successfully used for isolation of the CD133+ subset from GBC-SD cells. Furthermore, the CD133+ subset revealed an increased potential for tumor formation, cell proliferation, invasion and resistance to chemotherapeutic agents with expression of stem cell-associated genes. Therefore, in GBC-SD cells, the CXCR4/Akt/CD133 signaling pathways may be activated.

AKT activity is elevated in aggressive thyroid neoplasms where it promotes proliferation and invasion

The PI3K/AKT/mTOR signaling pathway controls major cellular processes such as cell growth, proliferation and survival. Stimulation of this pathway leads to AKT phosphorylation and activation, resulting in phosphorylation of mTOR and myriad other targets. AKT upregulation has been implicated in thyroid cancer pathogenesis and is a candidate treatment target for patients with advanced disease that has not responded to traditional therapies. Here we evaluate a large series of benign and malignant thyroid tumors for AKT activity and intracellular distribution. We also deplete AKT from multiple thyroid cancer cell lines, including putative cancer stem cell lines, and measure the effect on proliferation and invasion in vitro. We show that active AKT has a predominantly nuclear distribution and its expression is highest in anaplastic thyroid carcinomas and papillary thyroid carcinomas, including encapsulated and invasive follicular variants. Depletion of AKT in thyroid carcinoma cell lines led to greatly reduced proliferative capacity and resulted in a reduction of invasive potential. A reduction in invasion was also observed in the cancer stem cell compartment. Targeting AKT activity in the clinical setting may slow the growth and spread of aggressive thyroid neoplasms, and target the tumor stem cell compartment.

UCH-L1 promotes invasion of breast cancer cells through activating Akt signaling pathway

As a de-ubiquitin enzyme, ubiquitin C-terminal hydrolase (UCH)-L1 has been shown to be overexpressed in several human cancers. However, the function of UCH-L1 in invasion of breast cancers is still unclear. Here we report that the expression of UCH-L1 is significantly higher in cancer cells with higher invasive ability. While ectopic UCH-L1 expression failed to alter cell proliferation in MCF-7 cells, it caused a significant upregulation of cellular invasion. Furthermore, siRNA mediated knockdown of UCH-L1 led to suppression of invasion in UCH-L1 overexpressing MCF-7 cells. In order to identify molecular mechanisms underlying these observations, a novel in vitro proximity-dependent biotin identification method was developed by fusing UCH-L1 protein with a bacterial biotin ligase (Escherichia coli BirA R118G, BioID). Streptavidin magnetic beads pulldown assay revealed that UCH-L1 can interact with Akt in MCF-7 cells. Pulldown assay with His tagged recombinant UCH-L1 protein and cell lysate from MCF-7 cells further demonstrated that UCH-L1 preferentially binds to Akt2 for Akt activation. Finally, we demonstrated that overexpression of UCH-L1 led to activation of Akt as evidenced by upregulation of phosphorylated Akt. Thus, these findings demonstrated that UCH-L1 promotes invasion of breast cancer cells and might serve as a potential therapeutic target for treatment of human patients with breast cancers.

A Concise Atlas of Thyroid Cancer Next-Generation Sequencing Panel ThyroSeq v.2

The next-generation sequencing technology allows high out-put genomic analysis. An innovative assay in thyroid cancer, ThyroSeq® was developed for targeted mutation detection by next generation sequencing technology in fine needle aspiration and tissue samples. ThyroSeq v.2 next generation sequencing panel offers simultaneous sequencing and detection in >1000 hotspots of 14 thyroid cancer-related genes and for 42 types of gene fusions known to occur in thyroid cancer. ThyroSeq is being increasingly used to further narrow the indeterminate category defined by cytology for thyroid nodules. From a surgical perspective, genomic profiling also provides prognostic and predictive information and closely relates to determination of surgical strategy. Both the genomic analysis technology and the informatics for the cancer genome data base are rapidly developing. In this paper, we have gathered existing information on the thyroid cancer-related genes involved in the initiation and progression of thyroid cancer. Our goal is to assemble a glossary for the current ThyroSeq genomic panel that can help elucidate the role genomics play in thyroid cancer oncogenesis.

Association of Sp1 and survivin in epithelial ovarian cancer: Sp1 inhibitor and cisplatin, a novel combination for inhibiting epithelial ovarian cancer cell proliferation

The expression of specificity protein 1 (Sp1) and survivin was evaluated in clinical specimens of epithelial ovarian cancer (EOC) patients. When compared to normal tissue, EOC samples showed high expression of Sp1 and survivin using qPCR (Sp1: ∼2-fold; survivin: ∼5-fold) and Western blot (Sp1: >2.6-fold; survivin: >100-fold). The Sp1 inhibitor, and anti-cancer small molecule, tolfenamic acid (TA), was tested to enhance the response of Cisplatin (Cis) in EOC cell lines. Cell viability (CellTiter-Glo), combination index (CalcuSyn software), apoptosis (Annexin-V staining), cell cycle analyses (flow cytometry), and reactive oxygen species (flow cytometry) were determined. Cell migration and invasion was assessed using matrigel coated transwell chambers. Agilent Technologies proteomics analysis identified potential signaling pathways involved. The combination of TA (50 μM) and Cis (5 μM) synergistically increased the growth inhibition in ES2 (∼80 %, p < 0.001) and OVCAR-3 (60 %, p < 0.001) cells. TA or TA + Cis treatment in ES2 cells caused cell cycle arrest in G1 Phase (TA) or S-Phase (TA + Cis) and unregulated reactive oxygen species. Invasion and migration was decreased in ES2 cells. Global proteomic profiling showed modulation of proteins associated with oxidative phosphorylation, apoptosis, electron transport chain, DNA damage, and cell cycle proteins. These results demonstrate an association of Sp1 and survivin in EOC and confirm targeting these candidates with TA potentially sensitizes EOC cells to cisplatin.

Immunohistochemical evaluation of the mTOR pathway in intra-oral minor salivary gland neoplasms

OBJECTIVES

The aim of this study was to investigate the expression of upstream and downstream molecules of the oncogenic mTOR signaling pathway in intra-oral minor salivary gland tumors (SGTs).

MATERIALS AND METHODS

Tissue samples consisted of 39 malignant and 13 benign minor SGTs, and 8 controls of normal minor salivary glands (NMSG). An immunohistochemical analysis for phosphorylated Akt, 4EBP1 and S6 (total and phosphorylated), and eIF4E was performed.

RESULTS

Expression of pAkt and 4EBP1 was observed in all SGTs and in most NMSG. p4EBP1 was detected in almost all SGT cases, NMSG being negative. S6 immunoreactivity was observed in 37.5% of NMSG, 92.3% of benign and 100% of malignant SGTs, while pS6 expression was observed in 77% of benign and 95% of malignant SGTs, but not in NMSG. Finally, eIF4E was expressed in 12.5% of NMSG, 69.2% of benign, and 76.9% of malignant tumors. All molecules studied had statistically significantly lower expression in NMSG compared with SGTs. Moreover, malignant neoplasms received higher scores compared with benign tumors for all molecules with the exception of eIF4E.

CONCLUSION

The mTOR signaling pathway is activated in SGTs, especially in malignancies. Therefore, the possible therapeutic role of targeting the mTOR pathway by rapamycin analogs in SGTs needs further investigation.

Hypoxia-inducible factor 1α (HIF-1α) and reactive oxygen species (ROS) mediates radiation-induced invasiveness through the SDF-1α/CXCR4 pathway in non-small cell lung carcinoma cells

Radiotherapy is an important procedure for the treatment of inoperable non-small cell lung cancer (NSCLC). However, recent evidence has shown that irradiation can promote the invasion and metastasis of several types of cancer, and the underlying mechanisms are not fully understood. This study aimed to investigate the molecular mechanism by which radiation enhances the invasiveness of NSCLC cells. We found that after irradiation, hypoxia-inducible factor 1α (HIF-1α) was increased and translocated into the nucleus, where it bound to the hypoxia response element (HRE) in the CXCR4 promoter and promoted the transcription of CXCR4. Furthermore, reactive oxygen species (ROS) also plays a role in the radiation-induced expression of CXCR4. Our results revealed that 2 Gy X-ray irradiation promoted the metastasis and invasiveness of H1299, A549 and H460 cells, which were significantly enhanced by SDF-1α treatment. Blocking the SDF-1α/CXCR4 interaction could suppress the radiation-induced invasiveness of NSCLC cells. The PI3K/pAkt and MAPK/pERK1/2 pathways were found to be involved in radiation-induced matrix metalloproteinase (MMP) expression. In vivo, irradiation promoted the colonization of H1299 cells in the liver and lung, which was mediated by CXCR4. Altogether, our findings have elucidated the underlying mechanisms of the irradiation-enhanced invasiveness of NSCLC cells.

Integrin-linked kinase affects signaling pathways and migration in thyroid cancer cells and is a potential therapeutic target

BACKGROUND

Integrin-linked kinase (ILK) is a serine-threonine kinase that regulates interactions between the cell and the extracellular matrix. In many cancers, overexpression of ILK leads to increased cell proliferation, motility, and invasion. We hypothesized that ILK functions as a regulator of viability and migration in thyroid cancer cells.

METHODS

Eleven human thyroid cancer cell lines were screened for ILK protein expression. The cell lines with the greatest expression were treated with either ILK small interfering RNA (siRNA) or a novel ILK inhibitor, T315, and the effects were evaluated via Western blot and migration assay. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assays were performed to assess cell viability.

RESULTS

siRNA against ILK decreased phosphorylation of downstream effectors Akt and MLC, as well as decreased migration. Treatment with T315 showed a dose-related decrease in both Akt and MLC phosphorylation, as well as decreased migration. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assays showed T315 to have an half maximal inhibitory concentration of less than 1 μM in cell lines with high ILK expression.

CONCLUSION

ILK is expressed differentially in thyroid cancer cell lines. Both ILK siRNA and T315 inhibit motility of thyroid cancer cell lines, and T315 is shown to be cytotoxic at low concentrations. Altogether, our study suggests that ILK may represent an important kinase in aggressive thyroid cancers.

Combined inhibition of rho-associated protein kinase and EGFR suppresses the invasive phenotype in EGFR-dependent lung cancer cells

INTRODUCTION

Lung cancer remains the leading cause of cancer-related mortality worldwide, with metastatic disease frequently a prominent feature at the time of diagnosis. The role of NSCLC-derived EGFR mutations in cancer cell proliferation and survival has been widely reported, but little is known about the function of these mutations in invasive growth and metastasis. In this study, we sought to evaluate the intrinsic invasive properties of NSCLC cells with differing EGFR status and examine possible therapeutic targets that can abrogate invasive growth.

MATERIALS AND METHODS

Collagen-based assays and 3D cell cultures were used to assess morphological features, actin cytoskeleton dynamics and the invasive capacity of NSCLC cell lines with differing EGFR status. The role of the RhoA/ROCK/MYPT1 and EGFR/HER pathways in NSCLC-related invasion was investigated by pharmacological inhibition and RNA interference techniques.

RESULTS

We demonstrate a positive correlation between EGFR mutational/amplification status and invasive capacity. Knockdown of wild-type and mutant EGFR leads to depletion of active and total MYPT1 levels. Combined pharmacological inhibition or genetic ablation of ROCK/EGFR suppresses the hallmarks of cancer cells and abrogates the invasive phenotype in EGFR-dependent NSCLC cells.

CONCLUSIONS

These observations suggest that combined targeting of the ROCK and EGFR/HER pathways may be a potential therapeutic approach in limiting invasive growth in NSCLC.

PI3K/Akt/mTOR: A promising therapeutic target for non-medullary thyroid carcinoma

Thyroid carcinoma (TC) is the most common endocrine malignancy. The pathogenesis of TC is complex and involves multiple genetic events that lead to activation of oncogenic pathways such as the MAP kinase (MAPK) pathway and the PI3K/Akt/mTOR pathway. The PI3K/Akt pathway has emerged as an important player in the pathogenesis of TC, particularly in follicular and advanced anaplastic or poorly differentiated TC. Because these patients have a poor prognosis, particularly when their tumors become resistant to the conventional treatment with radioactive iodine, efforts have been made to identify possible targets for therapy within these pathways. Orally available drugs targeting the PI3K/Akt/mTOR pathway are being used with success in treatment of several types of malignant tumors. There is an increasing amount of preclinical and clinical data supporting that this pathway may represent a promising target for systemic therapy in TC. The present review focuses on the most recent developments on the role of the PI3K/Akt pathway in the pathogenesis of non-medullary TC and will provide insight into how this pathway can be targeted either alone or in the context of multimodal therapeutic strategies for treatment of advanced TC.

GLI1 Transcription Factor Affects Tumor Aggressiveness in Patients With Papillary Thyroid Cancers

A significant proportion of patients with papillary thyroid cancer (PTC) present with extrathyroidal extension (ETE) and lymph node metastasis (LNM). However, the molecular mechanism of tumor invasiveness in PTC remains to be elucidated. The aim of this study is to understand the role of Hedgehog (Hh) signaling in tumor aggressiveness in patients with PTC. Subjects were patients who underwent thyroidectomy from 2012 to 2013 in a single institution. Frozen or paraffin-embedded tumor tissues with contralateral-matched normal thyroid tissues were collected. Hh signaling activity was analyzed by quantitative RT-PCR (qRT-PCR) and immunohistochemical (IHC) staining. Datasets from Gene Expression Omnibus (GEO) (National Center for Biotechnology Information) were subjected to Gene Set Enrichment Analysis (GSEA). BRAFT1799A and telomerase reverse transcriptase promoter mutation C228T were analyzed by direct sequencing. Among 137 patients with PTC, glioma-associated oncogene homolog 1 (GLI1) group III (patients in whom the ratio of GLI1 messenger ribonucleic acid (mRNA) level in tumor tissue to GLI1 mRNA level in matched normal tissue was in the upper third of the subject population) had elevated risk for ETE (odds ratio [OR] 4.381, 95% confidence interval [CI] 1.414-13.569, P = 0.01) and LNM (OR 5.627, 95% CI 1.674-18.913, P = 0.005). Glioma-associated oncogene homolog 2 (GLI2) group III also had elevated risk for ETE (OR 4.152, 95% CI 1.292-13.342, P = 0.017) and LNM (OR 3.924, 95% CI 1.097-14.042, P = 0.036). GSEA suggested that higher GLI1 expression is associated with expression of the KEGG gene set related to axon guidance (P = 0.031, false discovery rate < 0.05), as verified by qRT-PCR and IHC staining in our subjects.GLI1 and GLI2 expressions were clearly related to aggressive clinicopathological features and aberrant activation of GLI1 involved in the axon guidance pathway. These results may contribute to development of new prognostic markers, as well as novel therapeutic targets.

The PI3K/Akt Pathway in Tumors of Endocrine Tissues

The phosphatidylinositol 3-kinase (PI3K)/Akt pathway is a key driver in carcinogenesis. Defects in this pathway in human cancer syndromes such as Cowden's disease and Multiple Endocrine Neoplasia result in tumors of endocrine tissues, highlighting its importance in these cancer types. This review explores the growing evidence from multiple animal and in vitro models and from analysis of human tumors for the involvement of this pathway in the following: thyroid carcinoma subtypes, parathyroid carcinoma, pituitary tumors, adrenocortical carcinoma, phaeochromocytoma, neuroblastoma, and gastroenteropancreatic neuroendocrine tumors. While data are not always consistent, immunohistochemistry performed on human tumor tissue has been used alongside other techniques to demonstrate Akt overactivation. We review active Akt as a potential prognostic marker and the PI3K pathway as a therapeutic target in endocrine neoplasia.

Nuclear stiffening inhibits migration of invasive melanoma cells

During metastasis, melanoma cells must be sufficiently deformable to squeeze through extracellular barriers with small pore sizes. We visualize and quantify deformability of single cells using micropipette aspiration and examine the migration potential of a population of melanoma cells using a flow migration apparatus. We artificially stiffen the nucleus with recombinant overexpression of Δ50 lamin A, which is found in patients with Hutchison Gilford progeria syndrome and in aged individuals. Melanoma cells, both WM35 and Lu1205, both show reduced nuclear deformability and reduced cell invasion with the expression of Δ50 lamin A. These studies suggest that cellular aging including expression of Δ50 lamin A and nuclear stiffening may reduce the potential for metastatic cancer migration. Thus, the pathway of cancer metastasis may be kept in check by mechanical factors in addition to known chemical pathway regulation.