Possible Involvement of Long Non-Coding RNAs GNAS-AS1 and MIR205HG in the Modulation of 5-Fluorouracil Chemosensitivity in Colon Cancer Cells through Increased Extracellular Release of Exosomes.

A growing number of studies have suggested the involvement of long non-coding RNAs as the key players in not just the initiation and progression of the tumor microenvironment, but also in chemotherapy tolerance. In the present study, generated 5-FU-resistant SW480/DR cells were analyzed via cDNA microarray for its aberrant lncRNAs and mRNAs expression in comparison with the 5-FU-susceptible SW480/DS cells. Among the 126 lncRNAs described, lncRNAs GNAS-AS1, MIR205HG, and LOC102723721 have been identified to be significantly upregulated, while lncRNs lnc-RP11-597K23.2.1-2, LOC100507639, and CCDC144NL-AS1 have been found to be significantly downregulated. In the meantime, bioinformatic analysis through gene ontology studies of aberrantly expressed mRNAs revealed "regulated exocytosis", among others, as the biological process most impacted in SW480/DR cells. To investigate, exosome purification was then carried out and its characterization were validated via transmission electron microscopy and nanoparticle tracking analysis. Interestingly, it was determined that the 5-FU-resistant SW480/DR cells secretes significantly higher concentration of extracellular vesicles, particularly, exosomes when compared to the 5-FU-susceptible SW480/DS cells. Based on the lncRNA-mRNA interaction network analysis generated, lncRNA GNAS-AS1 and MIR205HG have been identified to be potentially involved in the incidence of 5-FU resistance in SW480 colon cancer cells through promoting increased release of exosomes into the intercellular matrix. Our study hopes not only to provide insights on the list of involved candidate lncRNAs, but also to elucidate the role exosomes play in the initiation and development of 5-FU chemotherapy resistance in colon cancer cells.

Comparative genomic and phenotypic analyses of pathogenic fungi Neoscytalidium dimidiatum and Bipolaris papendorfii isolated from human skin scraping.

Neoscytalidium dimidiatum and Bipolaris species are fungal plant pathogens that have been reported to cause human diseases. Recently, we have isolated numerous N. dimidiatum and Bipolaris species from the skin scrapings and nails of different patients. In this work, we have sequenced the genome of one strain of N. dimidiatum. The sequenced genome was compared to that of a previously reported Bipolaris papendorfii genome for a better understanding of their complex lifestyle and broad host-range pathogenicity. Both N. dimidiatum UM 880 (~ 43 Mb) and B. papendorfii UM 226 (~ 33 Mb) genomes include 11,015-12,320 putative coding DNA sequences, of which 0.51-2.49% are predicted transposable elements. Analysis of secondary metabolism gene clusters revealed several genes involved in melanin biosynthesis and iron uptake. The arsenal of CAZymes related to plants pathogenicity is comparable between the species, including genes involved in hemicellulose and pectin decomposition. Several important gene encoding keratinolytic peptidases were identified in N. dimidiatum and B. papendorfii, reflecting their potential pathogenic role in causing skin and nail infections. In this study, additional information on the metabolic features of these two species, such as nutritional profiling, pH tolerance, and osmotolerant, are revealed. The genomic characterization of N. dimidiatum and B. papendorfii provides the basis for the future functional studies to gain further insights as to what makes these fungi persist in plants and why they are pathogenic to humans.

Differential Regulation of NK Cell Receptors in Acute Lymphoblastic Leukemia.

Cancer immunotherapies are preferred over conventional treatments which are highly cytotoxic to normal cells. Focus has been on T cells but natural killer (NK) cells have equal potential. Concepts in cancer control and influence of sex require further investigation to improve successful mobilization of immune cells in cancer patients. Acute lymphoblastic leukemia (ALL) is a hematological malignancy mainly of B cell (B-ALL) and T cell (T-ALL) subtypes. Influence of ALL on NK cell is still unclear. Targeted next-generation sequencing was conducted on 62 activating/inhibitory receptors, ligands, effector, and exhaustion molecules on T-ALL (6 males) and normal controls (NC) (4 males and 4 females). Quantitative PCR (q-PCR) further investigated copy number variation (CNV), methylation index (MI), and mRNA expression of significant genes in T-ALL (14 males), NC (12 males and 12 females), and B-ALL samples (N = 12 males and 12 females). Bioinformatics revealed unique variants particularly rs2253849 (T>C) in KLRC1 and rs1141715 (A>G) in KLRC2 only among T-ALL (allele frequency 0.8-1.0). Gene amplification was highest in female B-ALL compared to male B-ALL (KLRC2, KLRC4, and NCR3, p < 0.05) and lowest in male T-ALL cumulating in deletion of KLRD1 and CD69. MI was higher in male ALL of both subtypes compared to normal (KIR2DL1-2 and 4 and KIR2DS2 and 4, p < 0.05) as well as to female B-ALL (KIR3DL2 and KIR2DS2, p < 0.05). mRNA expressions were low. Thus, ALL subtypes potentially regulated NK cell suppression by different mechanisms which should be considered in future immunotherapies for ALL.

Circulating miRNAs in Type 2 Diabetic Patients with and without Albuminuria in Malaysia.

INTRODUCTION: Diabetic kidney disease (DKD) remains the leading cause of chronic kidney disease. Dysregulation of circulating miRNAs has been reported, suggesting their pathological roles in DKD. This study aimed to investigate differentially expressed miRNAs in the sera of type 2 diabetes mellitus (T2DM) patients with and without albuminuria in a selected Malaysian population. METHOD: Forty-one T2DM patients on follow-up at a community clinic were divided into normo-(NA), micro-(MIC), and macroalbuminuria (MAC) groups. Differential levels of miRNAs in 12 samples were determined using the pathway-focused (human fibrosis) miScript miRNA qPCR array and was validated in 33 samples, using the miScript custom qPCR array (CMIHS02742) (Qiagen GmbH, Hilden, Germany). RESULTS: Trends of upregulation of 3 miRNAs in the serum, namely, miR-874-3p, miR-101-3p, and miR-145-5p of T2DM patients with MAC compared to those with NA. Statistically significant upregulation of miR-874-3p (p = 0.04) and miR-101-3p (p = 0.01) was seen in validation cohort. Significant negative correlations between the estimated glomerular filtration rate (eGFR) and miR-874-3p (p = 0.05), miR-101-3p (p = 0.03), and miR-145-5p (p = 0.05) as well as positive correlation between miR-874-3p and age (p = 0.03) were shown by Pearson's correlation coefficient analysis. CONCLUSION: Upregulation of previously known miRNA, namely, miR-145-5p, and possibly novel ones, namely, miR-874-3p and miR-101-3p in the serum of T2DM patients, was found in this study. There was a significant correlation between the eGFR and these miRNAs. The findings of this study have provided encouraging evidence to further investigate the putative roles of these differentially expressed miRNAs in DKD.

Expression of Killer Cell Immunoglobulin-like Receptors (KIR) in Sex-associated Malignancies

@#Introduction: Sex shapes immune response with possible consequence on tumor immune escape. Acute lymphoblastic leukemia (ALL) predominates in males while ovarian cancer (OC) occurs in females. NK cells essential for tumor killing may have male preponderance. Association of sex, NK cell activity and malignancies is unclear. We hypothesize that sex differentially affects KIR expressions in sex-biased cancers. Method: Expression of inhibitory (KIR2DL1-5 and KIR3DL1-3) and activating (KIR2DS1-2 and 4-5 and KIR3DS1) genes in B-, T-cell ALL, OC and normal controls were determined by reverse-transcription polymerase-chain-reaction. Result: All normal males (but not females) expressed the framework genes and generally maintained haplotype A, except KIR3DL1. Normal females expressed more activating KIRs. Frequencies of KIR2DL1, 2DL4 and 2DS2 were significantly reduced among ovarian cancer patients. Sex difference in frequencies of KIR expression was not detected in ALL as majority were undetectable except framework gene KIR3DL2, was more frequent among T-ALL. Conclusion: Cancers may be associated with reduced KIR expression and influence of sex requires investigation.

Recent Updates on Mechanisms of Resistance to 5-Fluorouracil and Reversal Strategies in Colon Cancer Treatment.

5-Fluorouracil (5-FU) plus leucovorin (LV) remain as the mainstay standard adjuvant chemotherapy treatment for early stage colon cancer, and the preferred first-line option for metastatic colon cancer patients in combination with oxaliplatin in FOLFOX, or irinotecan in FOLFIRI regimens. Despite treatment success to a certain extent, the incidence of chemotherapy failure attributed to chemotherapy resistance is still reported in many patients. This resistance, which can be defined by tumor tolerance against chemotherapy, either intrinsic or acquired, is primarily driven by the dysregulation of various components in distinct pathways. In recent years, it has been established that the incidence of 5-FU resistance, akin to multidrug resistance, can be attributed to the alterations in drug transport, evasion of apoptosis, changes in the cell cycle and DNA-damage repair machinery, regulation of autophagy, epithelial-to-mesenchymal transition, cancer stem cell involvement, tumor microenvironment interactions, miRNA dysregulations, epigenetic alterations, as well as redox imbalances. Certain resistance mechanisms that are 5-FU-specific have also been ascertained to include the upregulation of thymidylate synthase, dihydropyrimidine dehydrogenase, methylenetetrahydrofolate reductase, and the downregulation of thymidine phosphorylase. Indeed, the successful modulation of these mechanisms have been the game plan of numerous studies that had employed small molecule inhibitors, plant-based small molecules, and non-coding RNA regulators to effectively reverse 5-FU resistance in colon cancer cells. It is hoped that these studies would provide fundamental knowledge to further our understanding prior developing novel drugs in the near future that would synergistically work with 5-FU to potentiate its antitumor effects and improve the patient's overall survival.

Isolation and Identification of Long Non-Coding RNAs in Exosomes Derived from the Serum of Colorectal Carcinoma Patients.

Long non-coding RNAs (lncRNAs) are non-coding RNAs consisting of more than 200 nucleotides in length. LncRNAs present in exosomes may play a critical role in the cellular processes involved in cancer pathogenesis and progression including proliferation, invasion, and migration of tumor cells. This paper aims to identify the differential expression of exosomal lncRNAs derived from the sera of non-cancer individuals and patients diagnosed with colorectal carcinoma. These differentially-expressed exosomal serum lncRNAs may provide an insight into the pathogenesis and progression of colorectal cancer (CRC). Serum exosomes and exosomes from SW480-7 cell culture supernatants were isolated and viewed by transmission electron microscope (TEM). The particle size distribution and protein markers of exosomes derived from SW480-7 were further analyzed using the Zetasizer Nano S instrument and western blotting technique. TEM showed that exosomes derived from serum and SW480-7 cells were round vesicles with sizes ranging from 50-200 nm. The exosomes derived from SW480-7 had an average diameter of 274.6 nm and contained the exosomal protein, ALIX/PDCD6IP. In our clinical studies, six lncRNAs, namely GAS5, H19, LINC00152, SNHG16, RMRP, and ZFAS1 were detected in the exosomes from sera of 18 CRC patients. Among these six lncRNAs, the expression level of LINC00152 was found to be significantly lower in CRC patients as compared to non-cancer individuals (p = 0.04) while lncRNA H19 was significantly up-regulated in advanced-stages (stage III and IV) of CRC (p = 0.04) as compared to early-stages (stage I and II). In conclusion, the detection of lower LINC00152 in exosomes of sera from CRC patients versus non-cancer individuals and H19 upregulation in advanced stages suggests that they may play important roles in pathogenesis and progression of CRC.

Loss of Interleukin-17RA Expression is Associated with Tumour Progression in Colorectal Carcinoma.

Interleukin-17 (IL-17) is a pro-inflammatory cytokine found in various cancers. Current evidence indicates that IL-17 plays a vital role in tumour initiation and progression in colorectal carcinoma (CRC) via binding with its receptor, IL-17RA. However, the association between clinicopathological features and presence of IL-17 and IL-17RA protein in primary CRC tissues remains unclear. This study also investigates the difference between the presence of IL-17 and IL-17RA in the paired tumour tissues versus adjacent normal tissues. The presence of IL-17RA and IL-17 protein in primary CRC tissues was determined by immunohistochemistry. Associations between clinicopathological features and IL-17RA and IL-17 immunoreactivity, were analyzed by χ2 tests. We found that both IL-17RA (p = 0.001) and IL-17 (p = 0.025) in tumour cells of primary CRC tissues was significantly lower as compared to adjacent normal tissue. Positive immunoreactivity for IL-17RA and IL-17 were detected in 51.0% and 16.8% of tumour tissues, respectively. Furthermore, negative immunoreactivity of IL-17R was significantly associated with advanced stage according to TNM classifier (p = 0.027), high grade of tumour (p = 0.019), increased depth of tumour invasion (p = 0.023) and vascular invasion (p = 0.039). Positive IL-17 immunoreactivity was associated with advanced stage (p = 0.008) and lymph node metastasis (p = 0.008). Thus, this study suggests that the loss of IL-17RA expression occurs as tumour progresses and this may predict the aggressiveness of tumour whilst expression of IL-17 promotes tumour progression and lymph node metastasis. Thus, loss of IL-17RA could be a useful prognostic biomarker for tumour progression in CRC patients.

Effect of the miR-96-5p inhibitor and mimic on the migration and invasion of the SW480-7 colorectal cancer cell line.

The objectives of the present study were to identify the aberrant expression of microRNA (miRNA) in colorectal carcinoma (CRC) tissues from published miRNA profiling studies and to investigate the effects of the identified miRNA inhibitor and mimic miR-96-5p on CRC cell migration and invasion. The altered expression of the regulators of cytoskeleton mRNA in miR-96-5p inhibitor-transfected cells was determined. The miR-96-5p expression level in five CRC cell lines, HCT11, CaCo2, HT29, SW480 and SW620, and 26 archived paraffin-embedded CRC tissues were also investigated by reverse-transcriptase quantitative polymerase chain reaction (RT-qPCR). Cell viability in response to the miR-96-5p inhibitor and mimic transfections was determined by an MTT assay. A Matrigel invasion assay was conducted to select the invasive subpopulation designated SW480-7, by using the parental cell line SW480. The effects of miR-96-5p mimic- or inhibitor-transfected SW480-7 cells on cell migration and invasion were evaluated using the Transwell and Matrigel assays, and the change in expression of the regulators of cytoskeleton mRNAs was identified by Cytoskeleton Regulators RT2-Profiler PCR array followed by validation with RT-qPCR. CRC tissues exhibited a significant increase in miR-96-5p expression, compared with their matched normal adjacent tissues, indicating an oncogenic role for miR-96-5p. The results demonstrated that the miR-96-5p inhibitor decreased the migration of SW480-7 cells, but had no effect on invasion. This may be due to the promotion of cell invasion by Matrigel, which counteracts the blockade of cell invasion by the miR-96-5p inhibitor. The miR-96-5p mimic enhanced SW480-7 cell migration and invasion, as expected. It was determined that there was a >2.5 fold increase in the expression of genes involved in cytoskeleton regulation, myosin light chain kinase 2, pleckstrin homology like domain family B member 2, cyclin A1, IQ motif containing GTPase activating protein 2, Brain-specific angiogenesisinhibitor 1-associated protein 2 and microtubule-actin crosslinking factor 1, in miR-96-5p inhibitor-transfected cells, indicating that they are negative regulators of cell migration. In conclusion, the miR-96-5p inhibitor blocked cell migration but not invasion, and the latter may be due to the counteraction of Matrigel, which has been demonstrated to stimulate cell invasion.

Identifying Common Mutations in Colorectal Cancer Using a 7-Gene Panel by Next Generation Sequencing

Abstract@#Introduction: Colorectal cancer (CRC) arises from the cumulative effects of genetic and epigenetic alterations. Current treatment of metastatic CRC relies on combination of chemotherapy and targeted therapies such as anti-EGFR therapies. The success of targeted therapies relies on the detection of actionable targets and predictive biomarkers of resistance. The study aims to determine mutations in common actionable targets and predictive biomarkers of resistance to anti-EGFR therapies in Malaysian CRC patients. Methods: Mutations in 10 CRC tissues were determined by next-generation sequencing with a panel of 7 cancer-related genes covering all exons in KRAS, BRAF, PIK3CA, PTEN, TP53, NRAS, and EGFR genes. Immunohistochemistry was used to determine mismatch repair (MMR) status. Results: Of the ten samples, 5 and 4 samples harboured two and one mutation, respectively and one had no mutation. All were missense mutations and were in five genes, namely, KRAS, PIK3CA, TP53, BRAF, and EGFR. They were, G12D, G12V, G12A, G13D, and V14I in KRAS, E545K, K733R, and D1056N in PIK3CA, G199V, D259Y, and R282W in TP53, V600E in BRAF and G696R in EGFR. Deficient mismatch repair (dMMR) was detected in three samples, of which two had KRAS mutation. Conclusion: Mutations in KRAS codon 12 and 13, BRAF and PIK3CA which predict resistance to anti-EGFR therapies and three TP53 mutations were found. This is the first report of EGFR mutation in Malaysian CRC patients. It is predicted to be a pathogenic variant. dMMR, one of the biomarkers for treatment with immune checkpoint inhibitor was also detected.

Association between polymorphisms of interleukin-17A G197A and interleukin-17F A7488G and risk of colorectal cancer.

BACKGROUND: Interleukin (IL)-17A and IL-17F are inflammatory cytokines mainly produced by T helper 17 cells. IL-17A is known to be protumorigenic while IL-17F has a protective role in cancer. A number of studies have been conducted to determine the association between polymorphisms of IL-17AG197A (rs2275913) and IL-17FA7488G (rs763780) and risk of cancers. No studies have yet to be conducted to genotype the IL-17AG197A polymorphism in colorectal cancer (CRC). OBJECTIVE: To assess the association of IL-17AG197A and IL-17FA7488G polymorphisms with CRC risk. MATERIALS AND METHODS: We performed the genotyping by polymerase chain reaction-restriction fragment length polymorphism method on blood samples from 80 healthy individuals and paraffin-embedded tumor tissues from 70 CRC patients. RESULTS: Our study showed that IL-17A197AA genotype was significantly associated with an increased CRC risk with odds ratios of 6.08 (95% confidence interval [CI]: 2.25-16.42, P < 0.001) and 2.80 (95% CI: 1.23-6.35, P = 0.014), in comparison with GG and AG genotypes, respectively. However, IL-17FA7488G polymorphism was not significantly associated with CRC risk (P = 0.102). No significant association of IL-17AG197A and IL-17FA7488G polymorphisms with patient and tumor variables was found. CONCLUSION: This report from Malaysia shows the relationship of IL-17A197AA genotype with susceptibility to CRC.

Inhibition of cell migration and invasion by miR­29a­3p in a colorectal cancer cell line through suppression of CDC42BPA mRNA expression.

The objective of this study was to determine the effect of miR­29a­3p inhibitor on the migration and invasion of colorectal cancer cell lines (CRC) and the underlying molecular mechanisms. miR­29a­3p was detected using reverse transcription-quantitative polymerase chain reaction (RT­qPCR) in the CRC cell lines HCT11, CaCo2, HT29, SW480 and SW620. An invasive subpopulation designated SW480­7 was derived from the parental cell line, detected by Transwell and Transwell Matrigel assays. Cytoskeleton Regulators RT2 profiler PCR array and western blot analysis were utilized to identify the alterations in expression of downstream mRNAs. siRNA against CDC42BPA was transfected into SW480­7 and effects on cell migration and invasion were investigated. Data obtained showed that miR­29a­3p was detected in these five CRC cell lines. miR­29a­3p inhibitor had no effect on viability but stimulated cell migration and invasion of SW480­7 cells. In contrast, miR­29a­3p mimic suppressed cell migration and invasion. TargetScan miRBD and DIANA were employed to identify the potential direct target genes of miR­29a­3p in the Cytoskeleton Regulators RT2-Profiler PCR array. Cytoskeleton Regulators RT2-Profiler PCR array data showed that 3 out of the 5 predicted targets genes, CDC42BPA (2.33-fold), BAIAP2 (1.79-fold) and TIAM1 (1.77-fold), in the array were upregulated by miR­29a­3p. A significant increase in expression IQGAP2, PHLDB2, SSH1 mRNAs and downregulation of PAK1 mRNA was also detected with miR­29a­3p inhibition. Increase in CDC42BPA, SSH1 and IQGAP2 mRNA expression correlated with increased protein level in miR­29a­3p transfected SW-480-7 cells. Silencing of CDC42BPA (an enhancer of cell motility) partially abolished miR­29a­3p inhibitor-induced stimulation of cell migration and invasion. miR­29a­3p expression in stage II and III CRC is relatively lower than that of stage I CRC. However, the data need to be interpreted with caution due to the small sample size. In conclusion, inhibition of miR­29a­3p stimulates SW480­7 cell migration and invasion and downstream expression IQGAP2, PHLDB2, SSH1 mRNAs are upregulated whilst PAK1 mRNA is downregulated. Silencing of CDC42BPA expression partially reduces miR29a­3p inhibitor-induced migration and invasion of SW480­7 cells.

Advances in targeted and immunobased therapies for colorectal cancer in the genomic era.

Targeted therapies require information on specific defective signaling pathways or mutations. Advances in genomic technologies and cell biology have led to identification of new therapeutic targets associated with signal-transduction pathways. Survival times of patients with colorectal cancer (CRC) can be extended with combinations of conventional cytotoxic agents and targeted therapies. Targeting EGFR- and VEGFR-signaling systems has been the major focus for treatment of metastatic CRC. However, there are still limitations in their clinical application, and new and better drug combinations are needed. This review provides information on EGFR and VEGF inhibitors, new therapeutic agents in the pipeline targeting EGFR and VEGFR pathways, and those targeting other signal-transduction pathways, such as MET, IGF1R, MEK, PI3K, Wnt, Notch, Hedgehog, and death-receptor signaling pathways for treatment of metastatic CRC. Additionally, multitargeted approaches in combination therapies targeting negative-feedback loops, compensatory networks, and cross talk between pathways are highlighted. Then, immunobased strategies to enhance antitumor immunity using specific monoclonal antibodies, such as the immune-checkpoint inhibitors anti-CTLA4 and anti-PD1, as well as the challenges that need to be overcome for increased efficacy of targeted therapies, including drug resistance, predictive markers of response, tumor subtypes, and cancer stem cells, are covered. The review concludes with a brief insight into the applications of next-generation sequencing, expression profiling for tumor subtyping, and the exciting progress made in in silico predictive analysis in the development of a prescription strategy for cancer therapy.

Increased Expression of Phosphatidylinositol 3-Kinase p110α and Gene Amplification of PIK3CA in Nasopharyngeal Carcinoma.

Molecular alterations in PIK3CA oncogene that encodes the p110α catalytic subunit of phosphatidylinositol 3-kinase (PI3K p110α) are commonly found in human cancers. In this study, we examined the expression of PI3K p110α and PIK3CA gene amplification in 74 nasopharyngeal carcinoma (NPC) cases. Immunohistochemical staining demonstrated overexpression of PI3K p110α protein in 44.6% (33/74) of NPCs and 4.8% (2/42) of the adjacent normal nasopharyngeal mucosa. Copy number of PIK3CA gene was successfully analyzed in 51 of the total NPC cases and 19 non-malignant nasopharynx tissues by quantitative real-time PCR. Using mean + 2(standard deviation) of copy numbers in the non-malignant nasopharynx tissues as a cutoff value, PIK3CA copy number gain was found in 10 of 51 (19.6%) NPC cases. High PI3K p110α expression level was correlated with increased PIK3CA copy number (Spearman's rho =0.324, P = 0.02). PI3K p110α expression and PIK3CA copy number did not associate with Akt phosphorylation, and patient and tumor variables. This study suggests that PI3K p110α overexpression, which is attributed, at least in part, to PIK3CA gene amplification, may contribute to NPC pathogenesis. However, these molecular aberrations may not be responsible for activation of Akt signaling in NPC.

Differential Expression Patterns of Leukaemia Associated Genes in Leukaemia Cell Lines Compared to Healthy Controls

Introduction: The phenotype and genotype of cancer cells portray hallmarks of cancer which may have clinical value. Cancer cell lines are ideal models to study and confirm these characteristics. We previously established two subtracted cDNA libraries with differentially expressed genes from an acute myeloid leukaemia patient with poor prognosis (PP) and good prognosis (GP). Objective: To compare gene expression of the leukaemia associated genes with selected biological characteristics in leukaemia cell lines and normal controls. Methodology: Expression of 28 PP genes associated with early fetal/embryonic development, HOX-related genes, hematopoiesis and aerobic glycolysis/ hypoxia genes and 36 GP genes involved in oxidative phosphorylation, protein synthesis, chromatin remodelling and cell motility were examined in B-lymphoid (BV173, Reh and RS4;11) and myeloid (HL-60, K562) leukaemia cell lines after 72h in culture as well as peripheral blood mononuclear cells from healthy controls (N=5) using semi-quantitative polymerase chain reaction (PCR) method. Cell cycle profiles were analysed on flow cytometry while MTT cytotoxicity assay was used to determine drug resistance to epirubicin. Results: Genes expressed significantly higher in B-lymphoid leukaemia cell lines compared to healthy controls were mostly of the GP library i.e. oxidative phosphorylation (3/10), protein synthesis (4/11), chromatin remodelling (3/3) and actin cytoskeleton genes (1/5). Only two genes with significant difference were from the PP library. Cancer associated genes, HSPA9 and PSPH (GP library) and BCAP31 (PP library) were significantly higher in the B-lymphoid leukemia cell lines. No significant difference was observed between myeloid cell lines and healthy controls. This may also be due heterogeneity of cell lines studied. PBMC from healthy controls were not in cell cycle. G2/M profiles and growth curves showed B-lymphoid cells just reaching plateau after 72 hour culture while myeloid cells were declining. IC50 values from cytotoxicity assay revealed myeloid cell lines had an average 13-fold higher drug resistance to epirubicin compared to B-lymphoid cell lines. Only CCL1, was expressed at least two-fold higher in myeloid compared to B-lymphoid cell lines. In contrast, MTRNR2, EEF1A1, PTMA, HLA-DR, C6orf115, PBX3, ENPP4, SELL, and IL3Ra were expressed more than 2-fold higher in B-lymphoid compared to myeloid cell lines studied here. Conclusion: Thus, B-lymphoid leukaemia cell lines here exhibited active, proliferating characteristics closer to GP genes. Higher expression of several genes in B-lymphoid compared to myeloid leukaemia cell lines may be useful markers to study biological differences including drug resistance between lineages.

Subtractive Hybridization Identifies Stem Cell-Associated Genes in an Acute Myeloid Leukemia with Poor Prognosis

Introduction: Current prognostic markers have improved survival prediction, however, it has not advanced treatment strategies. Gene expression profiling may identify biological markers suitable as therapeutic targets. Leukaemia stem cell is associated with adverse outcome, however, its biological characteristics are still being investigated. We observed higher in vitro cell viability in acute myeloid leukaemia (AML) samples with poor prognosis, which may be stem cell related. Objective: The objective of this study was to profile highly expressed genes in an AML sample of poor prognosis/high viability and compare with a sample of good prognosis/low viability. Method: Subtractive hybridization was performed on two AML samples with high blast counts (>80%), a poor prognosis, PP (disease free survival, DFS12 months) sample. The PP sample had higher CD34+ counts (73% vs 46%) and higher cell viability than the GP sample. cDNA libraries were subsequently cloned and sequenced. Results: cDNA subtracted from the PP samples was identified as genes active during fetal/embryonic development (LCOR, CNOT1, ORMDL1), HOX- related genes (HOXA3, PBX3, SF3B1), hematopoiesis (SELL, IL-3RA) and aerobic glycolysis/hypoxia (PGK1, HIGD1A) -associated genes. Majority of GP clones isolated contained genes involved in oxidative phosphorylation, OXPHOS (COXs, ATPs, MTND4 and MTRNR2), protein synthesis (including ribosomal proteins, initiating and elongation factors), chromatin remodeling (H2AFZ, PTMA), cell motility (MALAT1, CALM2, TMSB4X), and mitochondria (HSPA9, MPO) genes. Conclusion: Thus, the PP sample exhibited stem cell-like features while the GP sample showed cells at a high level of cell activity. These genes are potential prognostic markers and targets for therapy.

Comparison of invasion by human microvascular endothelial cell lines in response to vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in a threedimensional (3D) cell culture system.

BACKGROUND: Immortalized human endothelial cells are widely used as in vitro models for debilitating conditions such as cancer, cardiovascular and ocular diseases. Human microvascular endothelial cell (HMEC-1) is immortalized via stable transfection with a gene encoding SV40 large antigen whilst telomerase-immortalized human microvascular endothelial (TIME) cells is immortalized by engineering the human telomerase catalytic protein (hTERT) into primary microvascular endothelial cells. Here, we established a three-dimensional (3D) spheroid invasion assay with HMEC-1 and TIME and compared the difference in their ability to invade through the collagen matrix in response to exogenous growth factors, namely vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF). METHODS: TIME and HMEC-1 spheroids were embedded in a collagen matrix. The spheroids were stimulated with exogenous growth factors, namely VEGF (50 ng/mL) and bFGF (200 ng/mL). Twelve points of invasion length from a spheroid was measured using image analysis software, Image J. Three independent experiments were conducted and data was analysis by GraphPad Instat software, version 3.05. RESULTS: TIME spheroid invasion was 16.5 fold higher with exogenous VEGF (50 ng/mL) and bFGF (200 ng/mL) treatment as compared to those cultured in complete growth medium only. In contrast, no significant difference was observed between HMEC-1 spheroids stimulated with and without exogenous growth factors, VEGF and bFGF. CONCLUSIONS: This is the first report on the establishment of a 3D-spheroid invasion assay with TIME cells. The requirement of VEGF and bFGF for TIME spheroids invasion is a novel finding. In addition, this assay offers an advantage over HMEC-1 for testing novel angiogenic agents since it is not affected by endogenously secreted growth factors.

Dual treatments targeting IGF-1R, PI3K, mTORC or MEK synergize to inhibit cell growth, induce apoptosis, and arrest cell cycle at G1 phase in MDA-MB-231 cell line.

Triple-negative breast cancers (TNBCs) are aggressive cancers that do not benefit from hormonal therapy or therapies that target HER2 receptors. Insulin-like growth factor 1 receptor (IGF-1R), which has been shown to be overexpressed in breast cancer, activates numerous downstream kinases that associate with cell proliferation and survival. This study compared the effects caused by dual treatments targeting IGF-1R, PI3K, mTORC, or MEK with those by single treatments in a TNBC cell line, MDA-MB-231. We used small-molecule kinase inhibitors, namely, NVP-AEW541, NVP-BKM120, KU0063794, and PD0325901 to target IGF-1R, PI3K, mTORC, and MEK, respectively. Combination treatments of PD0325901 with NVP-AEW541, NVP-BKM120 or KU0063794 and NVP-AEW541 with KU0063794 demonstrated a significant synergistic growth inhibition. These dual treatments increased apoptosis and/or cell cycle arrest at G0/G1 phase and enhanced the inhibition of phosphorylation of Akt or downstream molecules of mTORC1, as compared to the single treatments. Our study suggests that targeting multiple kinases in IGF-1R signaling may be a promising therapeutic approach.

In vitro modulation of probiotic bacteria on the biofilm of Candida glabrata.

A conspicuous new concept of pathogens living as the microbial societies in the human host rather than free planktonic cells has raised considerable concerns among scientists and clinicians. Fungal biofilms are communities of cells that possess distinct characteristic such as increased resistance to the immune defence and antimycotic agents in comparison to their planktonic cells counterpart. Therefore, inhibition of the biofilm may represent a new paradigm for antifungal development. In this study, we aim to evaluate the in vitro modulation of vulvovaginal candidiasis (VVC)-causing Candida glabrata biofilms using probiotic lactobacilli strains. Probiotic Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 were shown to have completely inhibited C. glabrata biofilms and the results were corroborated by scanning electron microscopy (SEM), which revealed scanty structures of the mixed biofilms of C. glabrata and probiotic lactobacilli strains. In addition, biofilm-related C. glabrata genes EPA6 and YAK1 were downregulated in response to the probiotic lactobacilli challenges. The present study suggested that probiotic L. rhamnosus GR-1 and L. reuteri RC-14 strains inhibited C. glabrata biofilm by partially impeding the adherence of yeast cells and the effect might be contributed by the secretory compounds produced by these probiotic lactobacilli strains. Further investigations are required to examine and identify the biofilm inhibitory compounds and the mechanism of probiotic actions of these lactobacilli strains.

Detection of medically important Candida species by absolute quantitation real-time polymerase chain reaction.

BACKGROUND: The number of invasive candidiasis cases has risen especially with an increase in the number of immunosuppressed and immunocom promised patients. The early detection of Candida species which is specific and sensitive is important in determining the correct administration of antifungal drugs to patients. OBJECTIVES: This study aims to develop a method for the detection, identification and quantitation of medically important Candida species through quantitative polymerase chain reaction (qPCR). MATERIALS AND METHODS: The isocitrate lyase (ICL) gene which is not found in mammals was chosen as the target gene of real-time PCR. Absolute quantitation of the gene copy number was achieved by constructing the plasmid containing the ICL gene which is used to generate standard curve. Twenty fungal species, two bacterial species and human DNA were tested to check the specificity of the detection method. RESULTS: All eight Candida species were successfully detected, identified and quantitated based on the ICL gene. A seven-log range of the gene copy number and a minimum detection limit of 10(3) copies were achieved. CONCLUSIONS: A one-tube absolute quantification real-time PCR that differentiates medically important Candida species via individual unique melting temperature was achieved. Analytical sensitivity and specificity were not compromised.