Hedgehog signalling molecule, SMO is a poor prognostic marker in bladder cancer.

INTRODUCTION: Hedgehog (HH) pathway is an important signalling cascade for growth and patterning during embryonic development. Constitutive activation of Hedgehog pathway can be found in various types of malignancies including medulloblastoma, basal cell carcinoma, gastrointestinal, breast, pancreatic, prostate cancer and leukaemia. Little is known about the expression and role of Hedgehog signalling in bladder cancer. MATERIALS AND METHODS: The purpose of this study was to investigate the immunohistochemical expression of SMO in 112 bladder cancer cases and determine their association with demographic and clinicopathological parameters. Bladder cancer tissues were obtained from the Hospital Kuala Lumpur. RESULTS: SMO was expressed in the cytoplasm of all cases of bladder cancer. 6 cases (5.4%) showed low expression, while 106 cases (94.6%) showed high expression. Positive expression of SMO protein was correlated with a few variables which include grade and stage of tumour, lymph node metastasis and distant metastasis. SMO expression showed statistically significant association with higher grade (p=0.001) and higher stage (p=0.042) of bladder cancer. SMO expression also showed borderline association with lymph node metastasis (p=0.056). CONCLUSION: These findings indicate that SMO expression may be a poor prognostic marker in bladder cancer.

Immunohistochemical expression of NANOG in urothelial carcinoma of the bladder.

Urothelial carcinoma is a common malignant neoplasm that has a poor prognosis and a high frequency of recurrence and metastasis. Constant disease surveillance with periodic and long term cystoscopy examination is necessary for management of the disease. However, the monitoring and therapy regimen is expensive, incurring a massive burden to patients and the government. Therefore, the development of specific biomarkers for urothelial carcinoma at an early stage and recurrence detection becomes a priority. Homeobox genes are a family of genes that are involved in tumourigenesis. They might be potential prognostic markers for urothelial carcinoma. The study investigated the expression pattern of NANOG which is one of a homeobox gene in different stages and grades of urothelial carcinoma. NANOG expressions were also correlated with patient demographic factors and clinicopathological parameters. The expression of NANOG in 100 formalin-fixed paraffin-embedded urothelial carcinoma tissues was determined by immunohistochemistry. Immunohistochemistry showed positive expression of NANOG in all specimens with detection in the cytoplasm, nuclei and the nuclear membrane of the cancer cells. The immunohistochemical expression of NANOG increased across stages and grades of the tumour. The expression of NANOG was not significantly associated with demographic factors; gender (p = 0.376), race (p = 0.718) and age (p = 0.058) as well as with most of the clinicopathological parameters; pathological stage (p = 0.144), grade (p = 0.625), lymph node involvement (p = 0.174) and distant metastasis (p = 0.228). However, NANOG expression showed significant correlation with tumour invasion (p = 0.019). We concluded that NANOG might be a potential biomarker for early diagnosis of urothelial carcinoma of the bladder.

Dynamics of PEGylated-dextran-spermine nanoparticles for gene delivery to leukemic cells.

Leukemic cells are hard-to-transfect cell lines. Many transfection reagents which can provide high gene transfer efficiency in common adherent cell lines are not effective to transfect established blood cell lines or primary leukemic cells. This study aims to examine a new class of cationic polymer non-viral vector, PEGylated-dextran-spermine (PEG-D-SPM), to determine its ability to transfect the leukemic cells. Here, the optimal conditions of the complex preparation (PEG-D-SPM/plasmid DNA (pDNA)) were examined. Different weight-mixing (w/w) ratios of PEG-D-SPM/pDNA complex were prepared to obtain an ideal mixing ratio to protect encapsulated pDNA from DNase degradation and to determine the optimal transfection efficiency of the complex. Strong complexation between polymer and pDNA in agarose gel electrophoresis and protection of pDNA from DNase were detected at ratios from 25 to 15. Highest gene expression was detected at w/w ratio of 18 in HL60 and K562 cells. However, gene expression from both leukemic cell lines was lower than the control MCF-7 cells. The cytotoxicity of PEG-D-SPM/pDNA complex at the most optimal mixing ratios was tested in HL60 and K562 cells using MTS assay and the results showed that the PEG-D-SPM/pDNA complex had no cytotoxic effect on these cell lines. Spherical shape and nano-nature of PEG-D-SPM/pDNA complex at ratio 18 was observed using transmission electron microscopy. As PEG-D-SPM showed modest transfection efficiency in the leukemic cell lines, we conclude that further work is needed to improve the delivery efficiency of the PEG-D-SPM.

Clinical clues for head injuries amongst Malaysian infants: accidental or non-accidental?

Identifying the differences between infants with non-accidental head injuries (NAHI) and accidental head injuries (AHI) may help alert clinicians to recognize markers of abuse. A retrospective review of infants <1 year of age admitted to a tertiary referral centre in Malaysia over a two year period with a diagnosis of head injury or abnormal computed tomography head scans was conducted to identify the clinical features pointing towards a diagnosis of NAHI by comparing the socio-demographics, presenting complaints, clinical features and the extent of hospital investigations carried out. NAHI infants were more likely to be symptomatic, under a non-related caregiver's supervision, and presented with inconsistent or no known mechanism of injury. Subdural haemorrhages were more common in NAHI infants. The history, mechanism of injury, presenting signs and symptoms as well as the nature of the injuries sustained are all valuable clues as to whether a head injury sustained during infancy is likely to be accidental or not.

Induced pluripotent stem cells: history, properties and potential applications.

The development of induced pluripotent stem cells (iPSCs) has been met with much enthusiasm and hailed as a breakthrough discovery by the scientific and research communities amidst the divisive and ongoing debates surrounding human embryonic stem cells (hESC) research. The discovery reveals the fact that embryonic pluripotency can be generated from adult somatic cells by the induction of appropriate transcriptional factor genes essential for maintaining the pluripotency. They provide an alternative source for pluripotent stem cells, thus representing a powerful new research tool besides their potential application in the field of regenerative medicine. In this review, the historical background of iPSCs generation will be discussed together with their properties and characteristics as well as their potential therapeutic applications.

MT1-MMP regulates urothelial cell invasion via transcriptional regulation of Dickkopf-3.

Membrane type-1 matrix metalloproteinase (MT1-MMP) is a zinc-binding endopeptidase, which plays a crucial role in tumour growth, invasion and metastasis. We have shown previously that MT1-MMP has higher expression levels in the human urothelial cell carcinoma (UCC) tissue. We show here that siRNA against MT1-MMP blocks invasion in UCC cell lines. Invasion is also blocked by broad-spectrum protease and MMP inhibitors including tissue inhibitor of metalloproteinase-1 and -2. Membrane type-1-MMP can also regulate transcription. We have used expression arrays to identify genes that are differentially transcribed when siRNA is used to suppress MT1-MMP expression. Upon MT1-MMP knockdown, Dickkopf-3 (DKK3) expression was highly upregulated. The stability of DKK3 mRNA was unaffected under these conditions, suggesting transcriptional regulation of DKK3 by MT1-MMP. Dickkopf-3 has been previously shown to inhibit invasion. We confirm that the overexpression of DKK3 leads to decreased invasive potential as well as delayed wound healing. We show for the first time that the effects of MT1-MMP on cell invasion are mediated in part through changes in DKK3 gene transcription.

Comprehensive profiling and localisation of the matrix metalloproteinases in urothelial carcinoma.

The matrix metalloproteinases (MMPs) are endopeptidases which break down the extracellular matrix and regulate cytokine and growth factor activity. Several MMPs have been implicated in the promotion of invasion and metastasis in a broad range of tumours including urothelial carcinoma. In this study, RNA from 132 normal bladder and urothelial carcinoma specimens was profiled for each of the 24 human MMPs, the four endogenous tissue inhibitors of MMPs (TIMPs) and several key growth factors and their receptors using quantitative real time RT-PCR. Laser capture microdissection (LCM) of RNA from 22 tumour and 11 normal frozen sections was performed allowing accurate RNA extraction from either stromal or epithelial compartments. This study confirms the over expression in bladder tumour tissue of well-documented MMPs and highlights a range of MMPs which have not previously been implicated in the development of urothelial cancer. In summary, MMP-2, MT1-MMP and the previously unreported MMP-28 were very highly expressed in tumour samples while MMPs 1, 7, 9, 11, 15, 19 and 23 were highly expressed. There was a significant positive correlation between transcript expression and tumour grade for MMPs 1, 2, 8, 10, 11, 12, 13, 14, 15 and 28 (P < 0.001). At the same confidence interval, TIMP-1 and TIMP-3 also correlated with increasing tumour grade. LCM revealed that most highly expressed MMPs are located primarily within the stromal compartment except MMP-13 which localised to the epithelial compartment. This work forms the basis for further functional studies, which will help to confirm the MMPs as potential diagnostic and therapeutic targets in early bladder cancer.