Impact of HPV strains on molecular mechanisms of cervix cancer

PURPOSE

Cervical cancer accounts for a high number of deaths worldwide. Risk factors are extensive for cervix cancer but Human papillomavirus (HPV) plays a prime role in its development. Different strains of HPV are prevalent globally, which show different grades of mortality and morbidity among women. This study is planned to evaluate the molecular mechanism of different strains of HPV infection and progression leading to cervix cancer.

METHODS

This review includes different research articles on cervix cancer progression reported from India and all over the world.

RESULTS

HPV 16 and 18 are prevalent strains using heparan sulfate-independent and dependent pathways for viral replication inside the cell. It also uses transcription mechanisms through NF-kappa B, FOXA-1, and AP-1 genes while strains like HPV-35, 45, and 52 are also predominant in India, which showed a very slow mechanism of progression due to which mortality rate is low after their infection with these strains.

CONCLUSION

HPV uses E6 and E7 proteins which activate NF-kappa B and AP-1 pathway which suppresses the tumor suppressor gene and activates cytokine production, causing inflammation and leading to a decrease in apoptosis due to Caspase-3 activation. In contrast, the E7 protein involves HOXA genes and decreases apoptotic factors due to which mortality and incidence rates are low in viruses that use E7 motifs. Some HPV strains employ the cap-dependent pathway, which is also associated with lower mortality and infection rates.

SETBP1 accumulation induces P53 inhibition and genotoxic stress in neural progenitors underlying neurodegeneration in Schinzel-Giedion syndrome

The investigation of genetic forms of juvenile neurodegeneration could shed light on the causative mechanisms of neuronal loss. Schinzel-Giedion syndrome (SGS) is a fatal developmental syndrome caused by mutations in the SETBP1 gene, inducing the accumulation of its protein product. SGS features multi-organ involvement with severe intellectual and physical deficits due, at least in part, to early neurodegeneration. Here we introduce a human SGS model that displays disease-relevant phenotypes. We show that SGS neural progenitors exhibit aberrant proliferation, deregulation of oncogenes and suppressors, unresolved DNA damage, and resistance to apoptosis. Mechanistically, we demonstrate that high SETBP1 levels inhibit P53 function through the stabilization of SET, which in turn hinders P53 acetylation. We find that the inheritance of unresolved DNA damage in SGS neurons triggers the neurodegenerative process that can be alleviated either by PARP-1 inhibition or by NAD + supplementation. These results implicate that neuronal death in SGS originates from developmental alterations mainly in safeguarding cell identity and homeostasis.

Novel small molecule inhibitor of Kpnβ1 induces cell cycle arrest and apoptosis in cancer cells

Karyopherin beta 1 (Kpnβ1) is a major nuclear import receptor that mediates the import of cellular cargoes into the nucleus. Recently it has been shown that Kpnβ1 is highly expressed in several cancers, and its inhibition by siRNA induces apoptotic cancer cell death, while having little effect on non-cancer cells. This study investigated the effect of a novel small molecule, Inhibitor of Nuclear Import-60 (INI-60), on cancer cell biology, as well as nuclear import activities associated with Kpnβ1, and cancer progression in vivo using cervical and oesophageal cancer cell lines. INI-60 treatment resulted in the inhibition of cancer cell proliferation, colony formation, migration and invasion, and induced a G1/S cell cycle arrest, followed by cancer cell death via apoptosis. Non-cancer cells were minimally affected by INI-60 at concentrations that inhibited cancer cells. INI-60 treatment altered the localisation of Kpnβ1 and its cargoes, NFκB/p65, NFAT and AP-1, and the overexpression of Kpnβ1 reduced INI-60 cytotoxicity. INI-60 also inhibited KYSE 30 oesophageal cancer cell line growth in vivo. Taken together, these results show that INI-60 inhibits the nuclear import of Kpnβ1 cargoes and interferes with cancer cell biology. INI-60 presents as a potential therapeutic approach for cancers of different tissue origins and warrants further investigation as a novel anti-cancer agent.

A tight balance of Karyopherin β1 expression is required in cervical cancer cells

Background

Karyopherin β1 (Kpnβ1) is the main nuclear import protein involved in the transport of cargoes from the cytoplasm into the cell nucleus. Previous research has found Kpnβ1 to be significantly overexpressed in cervical cancer and other cancer tissues, and further studies showed that inhibition of Kpnβ1 expression by siRNA resulted in cancer cell death, while non-cancer cells were minimally affected. These results suggest that Kpnβ1 has potential as an anticancer therapeutic target, thus warranting further research into the association between Kpnβ1 expression and cancer progression. Here, the biological effects associated with Kpnβ1 overexpression were investigated in order to further elucidate the relationship between Kpnβ1 and the cancer phenotype.

Methods

To evaluate the effect of Kpnβ1 overexpression on cell biology, cell proliferation, cell cycle, cell morphology and cell adhesion assays were performed. To determine whether Kpnβ1 overexpression influences cell sensitivity to chemotherapeutic agents like Cisplatin, cell viability assays were performed. Expression levels of key proteins were analysed by Western blot analysis.

Results

Our data revealed that Kpnβ1 overexpression, above that which was already detected in cancer cells, resulted in reduced proliferation of cervical cancer cells. Likewise, normal epithelial cells showed reduced proliferation after Kpnβ1 overxpression. Reduced cancer cell proliferation was associated with a delay in cell cycle progression, as well as changes in the morphology and adhesion properties of cells. Additionally, Kpnβ1 overexpressing HeLa cells exhibited increased sensitivity to cisplatin, as shown by decreased cell viability and increased apoptosis, where p53 and p21 inhibition reduced and enhanced cell sensitivity to Cisplatin, respectively.

Conclusions

Overall, our results suggest that a tight balance of Kpnβ1 expression is required for cellular function, and that perturbation of this balance results in negative effects associated with a variety of biological processes.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-5044-8) contains supplementary material, which is available to authorized users.

KPNB1-mediated nuclear import is required for motility and inflammatory transcription factor activity in cervical cancer cells

Karyopherin β1 is a nuclear import protein involved in the transport of proteins containing a nuclear localisation sequence. Elevated Karyopherin β1 expression has been reported in cancer and transformed cells and is essential for cancer cell proliferation and survival. Transcription factors such as NFĸB and AP-1 contain a nuclear localisation sequence and initiate the expression of multiple factors associated with inflammation and cancer cell biology. Our study investigated the effect of inhibiting nuclear import via Karyopherin β1 on cancer cell motility and inflammatory signaling using siRNA and the novel small molecule, Inhibitor of Nuclear Import-43, INI-43. Inhibition of Karyopherin β1 led to reduced migration and invasion of cervical cancer cells. Karyopherin β1 is essential for the translocation of NFĸB into the nucleus as nuclear import inhibition caused its cytoplasmic retention and decreased transcriptional activity. A similar decrease was seen in AP-1 transcriptional activity upon Karyopherin β1 inhibition. Consequently reduced interleukin-6, interleukin-1 beta, tumour necrosis factor alpha and granulocyte macrophage colony stimulating factor expression, target genes of NFkB and AP-1, was observed. Migration studies inhibiting individual transcription factors suggested that INI-43 may affect a combination of signaling events. Our study provides further evidence that inhibiting KPNB1 has anti-cancer effects and shows promise as a chemotherapeutic target.

Targeting activator protein 1 signaling pathway by bioactive natural agents: Possible therapeutic strategy for cancer prevention and intervention

Activator protein 1 (AP-1) is a key transcription factor in the control of several cellular processes responsible for cell survival proliferation and differentiation. Dysfunctional AP-1 expression and activity are involved in several severe diseases, especially inflammatory disorders and cancer. Therefore, targeting AP-1 has recently emerged as an attractive therapeutic strategy for cancer prevention and therapy. This review summarizes our current understanding of AP-1 biology and function as well as explores and discusses several natural bioactive compounds modulating AP-1-associated signaling pathways for cancer prevention and intervention. Current limitations, challenges, and future directions of research are also critically discussed.

Targeting the Nuclear Import Receptor Kpnβ1 as an Anticancer Therapeutic

Karyopherin beta 1 (Kpnβ1) is a nuclear transport receptor that imports cargoes into the nucleus. Recently, elevated Kpnβ1 expression was found in certain cancers and Kpnβ1 silencing with siRNA was shown to induce cancer cell death. This study aimed to identify novel small molecule inhibitors of Kpnβ1, and determine their anticancer activity. An in silico screen identified molecules that potentially bind Kpnβ1 and Inhibitor of Nuclear Import-43, INI-43 (3-(1H-benzimidazol-2-yl)-1-(3-dimethylaminopropyl)pyrrolo[5,4-b]quinoxalin-2-amine) was investigated further as it interfered with the nuclear localization of Kpnβ1 and known Kpnβ1 cargoes NFAT, NFκB, AP-1, and NFY and inhibited the proliferation of cancer cells of different tissue origins. Minimum effect on the proliferation of noncancer cells was observed at the concentration of INI-43 that showed a significant cytotoxic effect on various cervical and esophageal cancer cell lines. A rescue experiment confirmed that INI-43 exerted its cell killing effects, in part, by targeting Kpnβ1. INI-43 treatment elicited a G2-M cell-cycle arrest in cancer cells and induced the intrinsic apoptotic pathway. Intraperitoneal administration of INI-43 significantly inhibited the growth of subcutaneously xenografted esophageal and cervical tumor cells. We propose that Kpnβ1 inhibitors could have therapeutic potential for the treatment of cancer. Mol Cancer Ther; 15(4); 560-73. ©2016 AACR.

Tissue invasion and metastasis: Molecular, biological and clinical perspectives

Cancer is a key health issue across the world, causing substantial patient morbidity and mortality. Patient prognosis is tightly linked with metastatic dissemination of the disease to distant sites, with metastatic diseases accounting for a vast percentage of cancer patient mortality. While advances in this area have been made, the process of cancer metastasis and the factors governing cancer spread and establishment at secondary locations is still poorly understood. The current article summarizes recent progress in this area of research, both in the understanding of the underlying biological processes and in the therapeutic strategies for the management of metastasis. This review lists the disruption of E-cadherin and tight junctions, key signaling pathways, including urokinase type plasminogen activator (uPA), phosphatidylinositol 3-kinase/v-akt murine thymoma viral oncogene (PI3K/AKT), focal adhesion kinase (FAK), β-catenin/zinc finger E-box binding homeobox 1 (ZEB-1) and transforming growth factor beta (TGF-β), together with inactivation of activator protein-1 (AP-1) and suppression of matrix metalloproteinase-9 (MMP-9) activity as key targets and the use of phytochemicals, or natural products, such as those from Agaricus blazei, Albatrellus confluens, Cordyceps militaris, Ganoderma lucidum, Poria cocos and Silybum marianum, together with diet derived fatty acids gamma linolenic acid (GLA) and eicosapentanoic acid (EPA) and inhibitory compounds as useful approaches to target tissue invasion and metastasis as well as other hallmark areas of cancer. Together, these strategies could represent new, inexpensive, low toxicity strategies to aid in the management of cancer metastasis as well as having holistic effects against other cancer hallmarks.

Neuronal nitric oxide synthase, as a downstream signaling molecule of c‑jun, regulates the survival of differentiated PC12 cells

The high expression of c-jun and neuronal nitric oxide synthase (nNOS) generally occurs in neurons following the generation of various animal models of central neuronal diseases. However, the mechanism between them in neuronal disease remains to be elucidated. Our previous studies demonstrated that the expression of c‑jun always occurs prior to expression of nNOS in motoneuron injuries and suppression of c‑jun expression by c‑jun siRNA decreased nNOS expression in differentiated PC12 cells. The present study aimed to examine whether there was an association of up and downstream regulation or crosstalk between c‑jun and nNOS in neurons. Using a culture of differentiated PC12 cells in vitro, the expression of nNOS and c-jun in cells was investigated by immunofluorescence. The nNOS inhibitor 7‑nitroindazole (7‑NI) was used in differentiated PC12 cells to downregulate the expression of nNOS. The optimal concentration of 7‑NI on the viability and survival of cultured differentiated PC12 cells was selected using a 3‑(4,5-dimethylthiazol-2-yl)‑2,5-diphenyltetrazolium assay and the effects of 7‑NI on the activity of constitutive nitric oxide synthase (cNOS) in differentiated PC12 cells were determined using a NOS Activity Detection kit. The effects of 7‑NI on the gene expression of nNOS and c‑jun were detected by western blot analysis. The results from the immunofluorescence demonstrated that the c‑jun and nNOS protein were constantly expressed in PC12 cells. The cell viability of differentiated PC12 cells were significantly inhibited by treatment with 200 and 400 µmol/l 7‑NI, and the expression levels of the nNOS protein were significantly inhibited by treatment with 200 µmol/l 7‑NI. However, 7‑NI had no significant effect on the protein expression level of c‑jun and the total activities of cNOS. Based on our previous studies, which revealed that the nNOS gene was a downstream signaling molecule of the JNK/c‑jun signaling pathway in cultured neurons, the expression of nNOS downstream was able to be regulated by c‑jun which was the upstream molecule. Therefore, these results indicated that the association between them involved up and downregulation instead of crosstalk.

The role of glycogen synthase kinase 3-β in immunity and cell cycle: implications in esophageal cancer

Esophageal cancer (EC) is one of the most aggressive gastrointestinal malignancies, possessing an insidious onset and a poor prognosis. Numerous transcription factors and inflammatory mediators have been reported to play a pivotal role in the initiation and progression of this cancer. However, the specifics of the signaling network responsible for said factors, especially which elements are the critical regulators, are still being elucidated. Glycogen synthesis kinases 3 (GSK3)β was originally regarded as a kinase regulating glucose metabolism. Accumulating evidence demonstrated that it also played an essential role in a variety of cellular processes including proliferation, differentiation, inflammation, motility, and survival by regulating various transcription factors such as c-Jun, AP-1, β-catenin, CREB, and NF-κB. Aberrant regulation of GSK3β has been shown to promote cell growth in some cancers, while suppressing it in others, and thus may play an important role in the development of EC. This review will discuss our current understanding of GSK3β signaling, and its control of the expression and activation of various transcription factors that mediate the inflammatory response. We will also explore some of the known mediators of EC progression, and based on current literature, elucidate the potential roles and implications of GSK3 in this disease.

p21-activated kinase 3 (PAK3) is an AP-1 regulated gene contributing to actin organisation and migration of transformed fibroblasts

Activating Protein 1 (AP-1) plays a vital role in cell proliferation, differentiation and apoptosis. While de-regulation of AP-1 has been linked to many cancers, little is known regarding its downstream transcriptional targets that associate with cellular transformation. Previous studies identified PAK3, a serine/threonine kinase, as a potential AP-1 target gene. PAK3 has been implicated in a variety of pathological disorders and over-expression of other PAK-family members has been linked to cancer. In this study, we investigate AP-1 regulation of PAK3 expression and the role of PAK3 in cJun/AP-1-associated cellular transformation. Our results showed elevated PAK3 expression at both the mRNA and protein level in cJun-over-expressing Rat1a fibroblasts, as well as in transformed human fibroblasts. Elevated PAK3 expression in cJun/AP-1 over-expressing cells associated with a significant increase in PAK3 promoter activation. This increased promoter activity was lost when a single putative Jun binding site, which can bind AP-1 directly both in vitro and in vivo, was mutated. Further, inhibition of PAK3 using siRNA showed a regression in the cell morphology, migratory potential and actin organisation associated with AP-1 transformed cells. Our study is a first to describe a role for AP-1 in regulating PAK3 expression and suggest that PAK3 is an AP-1 target required for actin organization and migration observed in transformed cells.

Association of c-Jun gene polymorphism with susceptibility to systemic lupus erythematosus in a Chinese population

C-Jun has been proved as playing an important role in the pathogenesis of tumors, as a main component of Activator protein 1 and c-Jun gene polymorphisms are associated with colorectal cancer. However, the relationship between the c-Jun gene polymorphism and the susceptibility to systemic lupus erythematosus (SLE) has not been known. Our purpose is to evaluate whether the c-Jun gene polymorphism (SNP rs3748814) is associated with susceptibility to SLE in a Chinese population. In this study, we enrolled 502 SLE patients and 652 healthy controls. The c-Jun polymorphism (rs3748814) was specified from genomic DNA using the TaqMan genotyping assay on a 7300 real-time reverse transcription polymerase chain reaction system. We found that the frequency of the A/G genotype in SLE patients was lower than in healthy controls, whereas the frequency of the G/G genotype was significantly higher in SLE patients than in healthy controls (A/G vs. G/G p = 8.670e-08, odds ratio [OR] = 0.290, 95% confidence interval [CI] = 0.184-0.456). In addition, the frequency of allele A in the patients group was significantly lower than in the control group (A vs. G p=5.221e-09, OR = 0.308, 95% CI = 0.212-0.466). The distribution of genotype and allele frequency in SLE patients with lupus nephritis (LN) compared with SLE patients without LN was not statistically significant (A/G vs. G/G p = 0.744, OR = 1.157, 95% CI=0.481-2.785; A vs. G p = 0.748, OR = 1.152, 95% CI = 0.486-2.734; A/A+A/G vs. G/G p = 0.744, OR = 1.157, 95% CI = 0.481-2.785). Furthermore, we did not find any significant association between other clinical features and genotypes. Our findings suggest that the c-Jun polymorphism (rs3748814) may be significantly associated with the susceptibility to SLE in a Chinese population.