Loss of heterozygosity among tumor suppressor genes in invasive and in situ carcinoma of the uterine cervix

Viral Inhibition of the IFN-Induced JAK/STAT Signalling Pathway: Development of Live Attenuated Vaccines by Mutation of Viral-Encoded IFN-Antagonists

The interferon (IFN) induced anti-viral response is amongst the earliest and most potent of the innate responses to fight viral infection. The induction of the Janus kinase/signal transducer and activation of transcription (JAK/STAT) signalling pathway by IFNs leads to the upregulation of hundreds of interferon stimulated genes (ISGs) for which, many have the ability to rapidly kill viruses within infected cells. During the long course of evolution, viruses have evolved an extraordinary range of strategies to counteract the host immune responses in particular by targeting the JAK/STAT signalling pathway. Understanding how the IFN system is inhibited has provided critical insights into viral virulence and pathogenesis. Moreover, identification of factors encoded by viruses that modulate the JAK/STAT pathway has opened up opportunities to create new anti-viral drugs and rationally attenuated new generation vaccines, particularly for RNA viruses, by reverse genetics.

Inactivation of PTCH1 is associated with the development of cervical carcinoma: clinical and prognostic implication

The aim of this study was to analyze the alterations of PTCH1 (deletion/promoter methylation/mutation/expression) during the development of cervical cancer (CACX). For this purpose, deletion/methylation of PTCH1 were analyzed in HPV16 positive exfoliated asymptomatic cervical swabs (n = 74), cervical intraepithelial neoplasia (CIN) (n = 32), CACX (n = 174) samples, and two CACX cell lines. The deletion of PTCH1 increased significantly from CIN (11.5%) to stage I/II (42%) and comparable in stage III/IV (46%). Low frequency (14-16%) of PTCH1 methylation was seen in the asymptomatic exfoliated cervical cells and in the normal epithelium adjacent to the tumor followed by a significant increase in CIN (31%) to stage I/II (57%) and comparable in stage III/IV (58%). The overall alterations (deletion/methylation) of PTCH1 significantly increased from CIN (34%) to stage I/II (70%) and comparable in stage III/IV (69%). Interestingly, in the normal epithelium, methylation of PTCH1 was high in basal/parabasal layers (83%), followed by decrease in the spinous layer (33 %), and showed significant inverse correlation with its expression. Reduced expression of PTCH1 seen in tumors showed a significant association with its alterations (deletion/methylation). The expression pattern of PTCH1 showed an inverse correlation with the nuclear expression of GLI1 in the normal epithelium as well as in the tumors. High nuclear expression of HPV16, E6, and E7 were seen in basal/parabasal layers of the normal epithelium and also in tumors. The PTCH1 alterations (deletion and/or methylation) in tumors and its methylation in adjacent normal epithelium were associated with poor prognosis of patients. Thus, our data suggests that activation of the Hedgehog pathway due to PTCH1 inactivation along with HPV infection is important in CACX development.

Type I interferon-sensitive recombinant newcastle disease virus for oncolytic virotherapy

Newcastle disease virus (NDV), an avian paramyxovirus, is tumor selective and intrinsically oncolytic because of its potent ability to induce apoptosis. Several studies have demonstrated that NDV is selectively cytotoxic to tumor cells but not normal cells due to defects in the interferon (IFN) antiviral responses of tumor cells. Many naturally occurring strains of NDV have an intact IFN-antagonistic function and can still replicate in normal human cells. To avoid potential toxicity issues with NDV, especially in cancer patients with immunosuppression, safe NDV-oncolytic vectors are needed. We compared the cell killing abilities of (i) a recombinant NDV (rNDV) strain, Beaudette C, containing an IFN-antagonistic, wild-type V protein (rBC), (ii) an isogenic recombinant virus with a mutant V protein (rBC-Edit virus) that induces increased IFN in infected cells and whose replication is restricted in normal human cells, and (iii) a recombinant LaSota virus with a virulent F protein cleavage site that is as interferon sensitive as rBC-Edit virus (LaSota V.F. virus). Our results indicated that the tumor-selective replication of rNDV is determined by the differential regulation of IFN-alpha and downstream antiviral genes induced by IFN-alpha, especially through the IRF-7 pathway. In a nude mouse model of human fibrosarcoma, we show that the IFN-sensitive NDV variants are as effective as IFN-resistant rBC virus in clearing the tumor burden. In addition, mice treated with rNDV exhibited no signs of toxicity to the viruses. These findings indicate that augmentation of innate immune responses by NDV results in selective oncolysis and offer a novel and safe virotherapy platform.

Enhanced expression of hedgehog signaling molecules in squamous cell carcinoma of uterine cervix and its precursor lesions

The hedgehog (Hh)-signaling pathway plays an essential role in normal development. Deregulation of this pathway is responsible for several types of cancers. The aim of this study was to determine the expression pattern and the extent of Hh-signaling molecules in squamous cell carcinoma of uterine cervix and its precursor lesions. A total of 106 uterine cervical cancers and related lesions (37 squamous cell carcinomas, 23 cervical intraepithelial neoplasia (CIN) III, 10 CIN II, four CIN I, 32 normal cervical epithelia) were immunohistochemically analyzed with anti-Shh, Indian Hh (Ihh), Patched (PTCH), Smoothened (Smo), Gli-1, Gli-2, Gli-3 antibodies on paraffin blocks. The results showed that the expression of all the Hh-signaling molecules was greatly enhanced in uterine cervical tumors, including carcinoma and its precursor lesions. The staining pattern was mainly cytoplasmic except for Gli-1/2, whose expression was observed in both cytoplasm and nucleus. In case of Ihh, PTCH, Smo and Gli-1, their expression in normal epithelium was completely absent or rare. The expression of all the seven Hh-signaling molecules mentioned above was significantly increased in CIN II/III and carcinoma, compared with that in normal epithelium (P < 0.05). The expression of Shh was increased by double; the first increase occurred in normal epithelium-CIN transition, and the second, during the progression of CIN to carcinoma. These results strongly suggest that the Hh-signaling pathways were extensively activated in carcinoma and CIN of uterine cervix. In conclusion, the Hh-signaling pathways may be involved in carcinogenesis of squamous cell carcinoma of uterine cervix and can be considered as a potential therapeutic target.