Probes for INS

Human gene mutations have revealed that a significant number of ADAMTS (a disintegrin-like and metalloproteinase (reprolysin type) with thrombospondin-type 1 motifs) proteins are necessary for normal ocular development and eye function. Mutations in human ADAMTSL4, encoding an ADAMTS-like protein which has been implicated in fibrillin microfibril biogenesis, cause ectopia lentis (EL) and EL et pupillae. Here, we report the first ADAMTSL4 mouse model, tvrm267, bearing a nonsense mutation in Adamtsl4. Homozygous Adamtsl4tvrm267 mice recapitulate the EL phenotype observed in humans, and our analysis strongly suggests that ADAMTSL4 is required for stable anchorage of zonule fibers to the lens capsule. Unexpectedly, homozygous Adamtsl4tvrm267 mice exhibit focal retinal pigment epithelium (RPE) defects primarily in the inferior eye. RPE dedifferentiation was indicated by reduced pigmentation, altered cellular morphology, and a reduction in RPE-specific transcripts. Finally, as with a subset of patients with ADAMTSL4 mutations, increased axial length, relative to age-matched controls, was observed and was associated with the severity of the RPE phenotype. In summary, the Adamtsl4tvrm267 model provides a valuable tool to further elucidate the molecular basis of zonule formation, the pathophysiology of ectopia lentis and ADAMTSL4 function in the maintenance of the RPE.

Alterations in genes that regulate brain size may contribute to both microcephaly and brain tumor formation. Here, we report that Aspm, a gene that is mutated in familial microcephaly, regulates postnatal neurogenesis in the cerebellum and supports the growth of medulloblastoma, the most common malignant pediatric brain tumor. Cerebellar granule neuron progenitors (CGNPs) express Aspm when maintained in a proliferative state by sonic hedgehog (Shh) signaling, and Aspm is expressed in Shh-driven medulloblastoma in mice. Genetic deletion of Aspm reduces cerebellar growth, while paradoxically increasing the mitotic rate of CGNPs. Aspm-deficient CGNPs show impaired mitotic progression, altered patterns of division orientation and differentiation, and increased DNA damage, which causes progenitor attrition through apoptosis. Deletion of Aspm in mice with Smo-induced medulloblastoma reduces tumor growth and increases DNA damage. Co-deletion of Aspm and either of the apoptosis regulators Bax or Trp53 (also known as p53) rescues the survival of neural progenitors and reduces the growth restriction imposed by Aspm deletion. Our data show that Aspm functions to regulate mitosis and to mitigate DNA damage during CGNP cell division, causes microcephaly through progenitor apoptosis when mutated, and sustains tumor growth in medulloblastoma.

Well-differentiated human cancers share transcriptional programs with the normal tissue counterparts from which they arise. These programs broadly influence cell behaviour and function and are integral modulators of malignancy. Here, we show that the master regulator of motile ciliogenesis, FOXJ1, is highly expressed in cells along the ventricular surface of the human brain. Strong expression is present in cells of the ependyma and the choroid plexus as well as in a subset of cells residing in the subventricular zone. Expression of FOXJ1 and its transcriptional program is maintained in many well-differentiated human tumours that arise along the ventricle, including low-grade ependymal tumours and choroid plexus papilloma. Anaplastic ependymoma as well as choroid plexus carcinoma show decreased FOXJ1 expression and its associated ciliogenesis program genes. In ependymoma and choroid plexus tumours, reduced expression of FOXJ1 and its ciliogenesis program are markers of poor outcome and are therefore useful biomarkers for assessing these tumours. Transitions in ciliogenesis define distinct differentiation states in ependymal and choroid plexus tumours with important implications for patient care.

APOBEC3B belongs to a protein family of cytidine deaminases that can insert mutations in DNA and RNA as a result of their ability to deaminate cytidine to uridine. It has been shown that APOBEC3B-catalysed deamination provides a chronic source of DNA damage in breast cancers. We investigated APOBEC3B expression in four drug resistant breast cancer cell lines (Doxorubicin, Etoposide, Paclitaxel and Docetaxel resistant MCF-7 cell lines) using a novel RNA in situ hybridization technology (RNAscope) and compared expression levels with drug sensitive MCF-7 cell line. After RNAscope staining, slides were scanned and saved as digital images using Aperio scanner and software. Quantitative scoring utilizing the number of punctate dots present within each cell boundary was performed for the parameters including positive cell percentage and signal intensity per positive cell. In Doxorubicin and Etoposide resistant MCF-7 cell lines, APOBEC3B expression was approximately five-fold increased (23% and 24% respectively) with higher signal intensity (1.92 and 1.44 signal/cell, respectively) compared to drug sensitive MCF-7 cell line (5%, 1.00 signal/cell) with statistical significance. The increase of APOBEC3B expression in Docataxel resitant and Paclitaxel resistant MCF-7 cell lines was not very high. In conclusion, APOBEC3B expression was increased in some population of tumor cells of drug resistant cell lines. At least for some drugs, APOBEC3B expression may be related to drug resistance, subjecting to some tumor cells to frequent mutation.

We genetically characterized seven nearly complete genomes in the protoparvovirus genus from the feces of children with diarrhea. The viruses, provisionally named cutaviruses (CutaV), varied by 1-6% nucleotides and shared ~76% and ~82% amino acid identity with the NS1 and VP1 of human bufaviruses, their closest relatives. Using PCR, cutavirus DNA was found in 1.6% (4/245) and 1% (1/100) of diarrhea samples from Brazil and Botswana respectively. In silico analysis of pre-existing metagenomics datasets then revealed closely related parvovirus genomes in skin biopsies from patients with epidermotropic cutaneous T-cell lymphoma (CTCL or mycosis fungoides). PCR of skin biopsies yielded cutavirus DNA in 4/17 CTCL, 0/10 skin carcinoma, and 0/21 normal or noncancerous skin biopsies. In situ hybridization of CTCL skin biopsies detected viral genome within rare individual cells in regions of neoplastic infiltrations. The influence of cutavirus infection on human enteric functions and possible oncolytic role in CTCL progression remain to be determined.

BACKGROUND:

The purpose of our research was to determine the prognostic impact and clinicopathological feature of c-MYC and β-catenin overexpression in colorectal cancer (CRC) patients.

METHODS:

Using immunohistochemistry (IHC), we measured the c-MYC and β-catenin expression in 367 consecutive CRC patientsretrospectively (cohort 1). Also, c-MYC expression was measured by mRNA in situ hybridization. Moreover, to analyze regional heterogeneity, three sites of CRC including the primary, distant and lymph node metastasis were evaluated in 176 advanced CRC patients (cohort 2).

RESULTS:

In cohort 1, c-MYC protein and mRNA overexpression and ß-catenin nuclear expression were found in 201 (54.8 %), 241 (65.7 %) and 221 (60.2 %) of 367 patients, respectively, each of which was associated with improved prognosis (P = 0.011, P = 0.012 and P = 0.033, respectively). Moreover, co-expression of c-MYC and ß-catenin was significantly correlated with longer survival by univariate (P = 0.012) and multivariate (P = 0.048) studies. Overexpression of c-MYC protein was associated with mRNA overexpression (ρ, 0.479; P < 0.001) and nuclear ß-catenin expression (ρ, 0.282; P < 0.001). Expression of c-MYC and ß-catenin was heterogeneous depending on location in advanced CRCpatients (cohort 2). Nevertheless, both c-MYC and ß-catenin expression in primary cancer were significantly correlated with improved survival in univariate (P = 0.001) and multivariate (P = 0.002) analyses. c-MYC and ß-catenin expression of lymph node or distant metastatic tumor was not significantly correlated with patients' prognosis (P > 0.05).

CONCLUSIONS:

Co-expression of c-MYC and ß-catenin was independently correlated with favorable prognosis in CRC patient. We concluded that the expression of c-MYC and ß-catenin might be useful predicting indicator of CRC patient's prognosis.

Grem1, an antagonist of bone morphogenetic proteins, plays a key role in embryogenesis. A highly specific temporospatial gradient of Grem1 and BMP signalling is critical to normal lung, kidney and limb development. Grem1 levels are increased in renal fibrotic conditions including acute kidney injury, diabetic nephropathy, chronic allograft nephropathy and immune glomerulonephritis. A small number of grem1-/- whole body knockout mice on a mixed genetic background (8 %) are viable, with a single, enlarged left kidney and grossly normal histology. Grem1-/- mice displayed mild renal dysfunction at 4 wk, which recovered by 16 wk. Tubular epithelial specific targeted deletion of Grem1 (Grem1-TEC-/-) mice displayed a milder response in both the acute injury and recovery phase of the folic acid model. Grem1-TEC-/- mice had smaller increases in indices of kidney damage compared to wild-type. In the recovery phase of the folic acid model, associated with renal fibrosis, Grem1-TEC-/- mice displayed reduced histological damage and an attenuated fibrotic gene response compared to wild-type controls. Together, these data demonstrated that Grem1 expression in the tubular epithelial compartment plays a significant role in the fibrotic response to renal injury in vivo.

Undifferentiated nasopharyngeal carcinoma (NPC) is a cancer with high metastatic potential that is consistently associated with Epstein-Barr virus (EBV) infection. In this study, we have investigated the functional contribution of sphingosine-1-phosphate (S1P) signalling to the pathogenesis of NPC. We show that EBV infection or ectopic expression of the EBV-encoded latent genes (EBNA1, LMP1 and LMP2A) can up-regulate sphingosine kinase 1 (SPHK1), the key enzyme that produces S1P, in NPC cell lines. Exogenous addition of S1P promotes the migration of NPC cells through the activation of AKT; shRNA knockdown of SPHK1 resulted in a reduction in the levels of activated AKT and inhibition of cell migration. We also show that S1P receptor 3 (S1PR3) mRNA is over-expressed in EBV-positive NPC patient-derived xenografts and a subset of primary NPC tissues, and that knockdown of S1PR3 suppressed the activation of AKT and the S1P-induced migration of NPC cells. Taken together, our data point to a central role for EBV in mediating the oncogenic effects of S1P in NPC and identify S1P signalling as a potential therapeutic target in this disease.