Plasmas for Treating Cancer: Opportunities for Adaptive and Self-Adaptive Approaches.

Plasma is an ionized gas that is typically formed under high-temperature laboratory conditions. Recent progress in atmospheric plasmas has led to cold atmospheric plasma (CAP) devices with ion temperatures close to room temperature. The unique chemical and physical properties of CAP have led to its use in various biomedical applications including cancer therapy.

Cold atmospheric plasma treatment selectively targets head and neck squamous cell carcinoma cells.

The treatment of locoregional recurrence (LRR) of head and neck squamous cell carcinoma (HNSCC) often requires a combination of surgery, radiation therapy and/or chemotherapy. Survival outcomes are poor and the treatment outcomes are morbid. Cold atmospheric plasma (CAP) is an ionized gas produced at room temperature under laboratory conditions.

Differential expression of colon cancer associated transcript1 (CCAT1) along the colonic adenoma-carcinoma sequence.

Background: The transition from normal epithelium to adenoma and, to invasive carcinoma in the human colon is associated with acquired molecular events taking 5-10 years for malignant transformation. We discovered CCAT1, a non-coding RNA over-expressed in colon cancer (CC), but not in normal tissues, thereby making it a potential disease-specific biomarker. We aimed to define and validate CCAT1 as a CC-specific biomarker, and to study CCAT1 expression across the adenoma-carcinoma sequence of CC tumorigenesis.

Single nucleotide polymorphism rs17849071 G/T in the PIK3CA gene is inversely associated with follicular thyroid cancer and PIK3CA amplification.

The proto-oncogene PIK3CA has been well studied for its activating mutations and genomic amplifications but not single nucleotide polymorphism (SNP) in thyroid cancer. We investigated SNP rs17849071 (minor allele G and major allele T) in PIK3CA in thyroid tumors in 503 subjects by PCR and sequencing of a region of intron 9 carrying this SNP. This SNP was found in both normal and thyroid tumor tissues as well as in different generations of a studied family, confirming it to be a germline genetic event in thyroid tumor patients.

A single nucleotide polymorphism in the human PIGK gene associates with low PIGK expression in colorectal cancer patients.

Colorectal cancer (CRC) represents one of the highest incidences of cancers worldwide. Phosphatidylinositol glycan, class K (PIGK), is a crucial member of the glycosyl-phosphatidylinositol transamidase (GPIT) protein complex that attaches a diverse group of macromolecules to the plasma membrane of eukaryotes. However, the precise role of PIGK in tumorigenesis remains largely unknown.

Thioridazine induces apoptosis by targeting the PI3K/Akt/mTOR pathway in cervical and endometrial cancer cells.

Recently, thioridazine (10-[2-(1-methyl-2-piperidyl) ethyl]-2-methylthiophenothiazine), a well-known anti-psychotic agent was found to have anti-cancer activity in cancer cells. However, the molecular mechanism of the agent in cellular signal pathways has not been well defined. Thioridazine significantly increased early- and late-stage apoptotic fraction in cervical and endometrial cancer cells, suggesting that suppression of cell growth by thioridazine was due to the induction of apoptosis.

Tumor suppressor BLU enhances pro-apoptotic activity of sMEK1 through physical interaction.

BLU is a tumor suppressor that acts as a transcriptional regulator through the association with cellular components. However, the working mechanism of BLU in cellular functions was not understood. We found that BLU directly interacts with sMEK1, a regulatory subunit of protein phosphatase 4.

BRAF mutation-selective inhibition of thyroid cancer cells by the novel MEK inhibitor RDEA119 and genetic-potentiated synergism with the mTOR inhibitor temsirolimus.

We examined the therapeutic potential of a novel MEK inhibitor, RDEA119, and its synergism with the mTOR inhibitor, temsirolimus, in thyroid cancer cell lines. RDEA119 potently inhibited the proliferation of the 4 cell lines that harbored BRAF mutation but had no or modest effects on the other 4 cells that harbored wild-type BRAF (IC(50) of 0.034-0.

Development of a microRNA-based molecular assay for the detection of papillary thyroid carcinoma in aspiration biopsy samples.

Background: Although thyroid nodules are common and diagnosed in over 5% of the adult population, only 5% harbor malignancy. Patients with clinically suspicious thyroid nodules need to undergo fine-needle aspiration biopsy (FNAB). The main limitation of FNAB remains indeterminate cytopathology.

The BRAFT1799A mutation confers sensitivity of thyroid cancer cells to the BRAFV600E inhibitor PLX4032 (RG7204).

Aberrant signaling of the Ras-Raf-MEK-ERK (MAP kinase) pathway driven by the mutant kinase BRAF(V600E), as a result of the BRAF(T1799A) mutation, plays a fundamental role in thyroid tumorigenesis. This study investigated the therapeutic potential of a BRAF(V600E)-selective inhibitor, PLX4032 (RG7204), for thyroid cancer by examining its effects on the MAP kinase signaling and proliferation of 10 thyroid cancer cell lines with wild-type BRAF or BRAF(T1799A) mutation. We found that PLX4032 could effectively inhibit the MAP kinase signaling, as reflected by the suppression of ERK phosphorylation, in cells harboring the BRAF(T1799A) mutation.

Presence of 5-methylcytosine in CpNpG trinucleotides in the human genome.

While the methylation machinery of mammalian cells has been shown to be capable of both maintenance and de novo methylation at CpNpG sites, CpNpG methylation in the human genome has not been demonstrated. Here, we report the first observation of 5-methylcytosines in CpNpG triplets in the human genome. We identify the existence of CpNpG methylation in a number of genes which contain trinucleotide repeat regions, including the androgen receptor (AR).

Neurofilament heavy polypeptide regulates the Akt-beta-catenin pathway in human esophageal squamous cell carcinoma.

Aerobic glycolysis and mitochondrial dysfunction are common features of aggressive cancer growth. We observed promoter methylation and loss of expression in neurofilament heavy polypeptide (NEFH) in a significant proportion of primary esophageal squamous cell carcinoma (ESCC) samples that were of a high tumor grade and advanced stage. RNA interference-mediated knockdown of NEFH accelerated ESCC cell growth in culture and increased tumorigenicity in vivo, whereas forced expression of NEFH significantly inhibited cell growth and colony formation.

Phospho-DeltaNp63alpha/NF-Y protein complex transcriptionally regulates DDIT3 expression in squamous cell carcinoma cells upon cisplatin exposure.

Cisplatin remains the most important chemotherapeutic agent for patients with human head and neck cancer. However, tumor cells often develop resistance to cisplatin-induced apoptosis. We previously found that head and neck squamous cell carcinoma (HNSCC) cells exposed to cisplatin display a marked ATM-induced phosphorylation of DeltaNp63alpha.

Loss of DeltaNp63alpha promotes invasion of urothelial carcinomas via N-cadherin/Src homology and collagen/extracellular signal-regulated kinase pathway.

p63 plays a critical role in normal development and maintenance of stratified epithelia, including the urothelium. In the normal urothelium, urothelial cells in the basal layers abundantly express the predominant p63 isoform DeltaNp63alpha. We previously showed that (a) DeltaNp63alpha expression at the similar level to the normal urothelium is retained in most low-grade papillary noninvasive (LPN) tumors, whereas frequently lost in high-grade invasive carcinomas, and that (b) loss of DeltaNp63alpha is associated with poor prognosis of invasive bladder urothelial carcinoma patients.

ATM kinase is a master switch for the Delta Np63 alpha phosphorylation/degradation in human head and neck squamous cell carcinoma cells upon DNA damage.

We previously found that the pro-apoptotic DNA damaging agent, cisplatin, mediated the proteasome-dependent degradation of Delta Np63 alpha associated with its increased phosphorylated status. Since Delta Np63 alpha usually plays an opposite role to p53 and TAp63 in human cancers, we tested the notion that phosphorylation events induced by DNA damage would affect the protein degradation of Delta Np63 alpha in HNSCC cells upon cisplatin exposure. We found that Delta Np63 alpha is phosphorylated in the time-dependent fashion at the following positions: S385, T397 and S466, which were surrounded by recognition motifs for ATM, CDK2 and p70s6K kinases, respectively.

ssDNA-binding protein 2 is frequently hypermethylated and suppresses cell growth in human prostate cancer.

Purpose: Prostate cancer is a major cause of cancer death among men and the development of new biomarkers is important to augment current detection approaches.

Experimental Design: We identified hypermethylation of the ssDNA-binding protein 2 (SSBP2) promoter as a potential DNA marker for human prostate cancer based on previous bioinformatics results and pharmacologic unmasking microarray. We then did quantitative methylation-specific PCR in primary prostate cancer tissues to confirm hypermethylation of the SSBP2 promoter, and analyzed its correlation with clinicopathologic data.

Profiling the expression pattern of GPI transamidase complex subunits in human cancer.

The glycosylphosphatidylinositol transamidase complex (GPIT) consists of five subunits: PIG-U, PIG-T, GPAA1, PIG-S and GPI8, and is important in attaching GPI anchors to target proteins. On the basis of our previous reports incriminating PIG-U as an oncogene in bladder cancer and PIG-T and GPAA1 as oncogenes in breast cancer, we evaluated the expression pattern of the GPIT subunits in 19 different human cancers at both mRNA and protein levels. In general, our results demonstrate a more frequent expression of GPIT subunits in cancers than in normal.

Midkine induces epithelial-mesenchymal transition through Notch2/Jak2-Stat3 signaling in human keratinocytes.

Epithelial-to-mesenchymal transition (EMT) underlies cell plasticity and embryonic development and is frequently observed in advanced tumorigenesis. We demonstrated that midkine (MK), a retinoic acid-inducible heparin-binding mitogen, promotes EMT in immortalized HaCaT keratinocytes. We showed that MK binds to the Notch2 receptor in HaCaT keratinocytes.

Overexpression of AQP5, a putative oncogene, promotes cell growth and transformation.

Overexpression of several aquaporins has been reported in different types of human cancer but the role of AQPs in human carcinogenesis has not yet been clearly defined. Here, we demonstrate that ectopic expression of human AQP5 (hAQP5), a water channel expressed in lung, salivary glands, and kidney, induces many phenotypic changes characteristic of transformation both in vitro and in vivo. Furthermore, the cell proliferative ability of AQP5 appears to be dependent upon the phosphorylation of a cAMP-protein kinase (PKA) consensus site located in a cytoplasmic loop of AQP5.

U-box-type ubiquitin E4 ligase, UFD2a attenuates cisplatin mediated degradation of DeltaNp63alpha.

DeltaNp63alpha, the dominant negative isoform of the p63 family is an essential survival factor in head and neck squamous cell carcinoma. This isoform has been shown to be down regulated in response to several DNA damaging agents, including cisplatin. But little is understood about the post-translational protein stability of DeltaNp63alpha.

Methylation of the DFNA5 increases risk of lymph node metastasis in human breast cancer.

The pathogenesis of breast cancer involves multiple genetic and epigenetic events. In this study, we report an epigenetic alteration of DFNA5 in human breast cancer. DFNA5 gene was silenced in breast cancer cell lines that were methylated in the DFNA5 promoter, and restored by treatment with the demethylating agent, 5-aza-dC, and gene knock-down of DFNA5 increased cellular invasiveness in vitro.

Hypermethylation of MCAM gene is associated with advanced tumor stage in prostate cancer.

Background: DNA methylation has emerged as a promising biomarker for prostate cancer detection. In this report, we screened 36 candidate genes generated by a bioinformatic analysis of the human genome, and found that the melanoma cell adhesion molecule (MCAM) was an excellent candidate for cancer-specific methylation in prostate cancer.

Methods: Direct sequencing of bisulfite-treated genomic DNA, conventional methylation-specific PCR (MSP), real-time quantitative methylation-specific PCR, immunohistochemistry, colony formation assay, and statistical analysis.

Membrane trafficking of AQP5 and cAMP dependent phosphorylation in bronchial epithelium.

Phosphorylation pathway has been identified as an important step in membrane trafficking for AQP5. We generated stably transfected BEAS-2B human bronchial epithelial cells with various over-expression constructs on permeable support. In stable cells with wild-type AQP5 and S156A (AQP5 mutant targeting PKA consensus sequence), AQP5 expression was predominantly polarized to the apical membrane, whereas stable cells with N185D (AQP5 mutant targeting second NPA motif), mainly localized to the cytoplasm.

Alterations of GPI transamidase subunits in head and neck squamous carcinoma.

Background: GPI anchor attachment is catalyzed by the GPI transamidase (GPIT) complex. GAA1, PIG-T and PIG-U are the three of five GPIT subunits. Previous studies demonstrated amplification and overexpression of GPIT subunits in bladder and breast cancer with oncogenic function.