Clinical relevance of human papillomavirus testing in cytopathology

Cancer of the uterine cervix is the second most common cancer in women worldwide. Currently, cervical screening is based on cytology alone. Because infection with high-risk human papillomavirus types (hrHPVs) is a necessary cause of cervical cancer, it has been postulated that screening might become more efficient when it is based on combined cytology and hrHPV testing. In this review we will discuss the advantages of added HPV tests in cervical cancer screening, as a quality control for false-negative smears, in triage of women with equivocal smears, in follow-up of women treated for CIN3 or cervical cancer and for the detection of cervical adenocarcinoma.     

Micronuclei as biomarkers for evaluating the risk of malignant transformation in the uterine cervix

We evaluated micronucleus and apoptosis occurrence among women with normal smears and women with different kinds of cervical abnormalities, i.e., inflammatory processes and low- and high-grade squamous intraepithelial lesions (N = 12, N = 10 and N = 27, respectively). The sample included 59 women who were seen at a public medical service for cervical cancer prevention in Feira de Santana, Bahia, Brazil. The diagnosis was established by means of cytological, colposcopic, and histopathological examination. Cytogenetic analysis was performed on 2000 cells from each woman and included assessment of micronuclei and nuclear degenerative abnormalities indicative of apoptosis (karyorrhexis, pyknosis and condensed chromatin). Micronucleus frequency was significantly higher in the women with high-grade squamous intraepithelial lesions than in the women without cervical abnormalities or inflammatory processes (P< 0.001) or in the women with low-grade squamous intraepithelial lesions (P < 0.005). The frequency of apoptosis was similar in women without cervical abnormalities and women showing high-grade squamous intraepithelial lesions (P > 0.50), and significantly lower in women without cervical abnormalities and in women showing high-grade squamous intraepithelial lesions than in women showing inflammatory processes or low-grade squamous intraepithelial lesions (P < 0.0001). These results indicate that, in addition to Papanicolaou cervical cytological analysis, it would be useful to use micronucleus analysis to screen women who are at risk of developing cervical cancer. The assessment of nuclear degenerative abnormalities indicative of apoptosis increased the sensitivity of this test.     

人乳头瘤病毒及其致瘤机制的研究进展

高危型人乳头瘤病毒（humanpa pilloma virus,HPV）的持续感染是导致妇女宫颈癌发生的一个关键因素。HPV感染宫颈上皮细胞后,可以通过抑制免疫应答,在部分个体中建立潜伏感染。高危HPV编码的蛋白在持续感染的过程中,操控了细胞多种重要功能,如凋亡、增殖、细胞周期调控等,使得宫颈上皮细胞的形态学、遗传物质、表观遗传学等都发生重要改变。部分感染人群的宫颈上皮细胞因此会被转化,并在协同因子相互作用下,逐渐转化为宫颈癌。HPV在宫颈癌发生过程中起着重要的作用,本文将对HPV感染致宫颈癌机制最近的研究进展进行综述。     

Acquired immune response to oncogenic human papillomavirus associated with prophylactic cervical cancer vaccines

Human papillomavirus (HPV) is a common infection among women and a necessary cause of cervical cancer. Oncogenic HPV types infecting the anogenital tract have the potential to induce natural immunity, but at present we do not clearly understand the natural history of infection in humans and the mechanisms by which the virus can evade the host immune response. Natural acquired immune responses against HPV may be involved in the clearance of infection, but persistent infection with oncogenic virus types leads to the development of precancerous lesions and cancer. B cell responses are important for viral neutralization, but antibody responses in patients with cervical cancer are poor. Prophylactic vaccines targeting oncogenic virus types associated with cervical cancer have the potential to prevent up to 80% of cervical cancers by targeting HPV types 16 and 18. Clinical data show that prophylactic vaccines are effective in inducing antibody responses and in preventing persistent infection with HPV, as well as the subsequent development of high-grade cervical intraepithelial neoplasia. This article reviews the known data regarding natural immune responses to HPV and those developed by prophylactic vaccination.     

Fibronectin promotes cervical cancer tumorigenesis through activating FAK signaling pathway

Cervical cancer is a cancer arising from the cervix, and it is the fourth most common cause of death in women. Overexpression of fibronectin 1 (FN1) was observed in many tumors and associated with the survival and metastasis of cancer cells. However, the mechanism by which FN1 promotes cervical cancer cell viability, migration, adhesion, and invasion, and inhibits cell apoptosis through focal adhesion kinase (FAK) signaling pathway remains to be investigated. Our results demonstrated that FN1 was upregulated in patients with cervical cancer and higher FN1 expression correlated with a poor prognosis for patients with cervical cancer. FN1 knockdown by small interfering RNA (siRNA) inhibited SiHa cell viability, migration, invasion, and adhesion, and promoted cell apoptosis. FN1 overexpression in CaSki cell promoted cell viability, migration, invasion, and adhesion, and inhibited cell apoptosis. Further, phosphorylation of FAK, a main downstream signaling molecule of FN1, and the protein expression of Bcl-2/Bax, matrix metalloproteinase 2 (MMP-2), matrix metalloproteinase 9 (MMP-9), and N-cadherin was upregulated in CaSki cells with FN1 overexpression, but caspase-3 protein expression was downregulated. The FAK phosphorylation inhibitor PF573228 inhibited FN1 overexpression-induced expression of those proteins in CaSki cells with FN1 overexpression. In vivo experiment demonstrated that FN1 knockdown significantly inhibited FN1 expression, phosphorylation of FAK, and tumor growth in xenograft from the nude mice. These results suggest that FN1 regulates the viability, apoptosis, migration, invasion, and adhesion of cervical cancer cells through the FAK signaling pathway and is a potential therapeutic target in the treatment of cervical cancer.     

Comparison of Serum and Tissue Levels of Trace Elements in Different Models of Cervical Cancer

Cervical cancer is a leading cause of death by cancer among women worldwide. It is necessary to develop and refine cervical cancer models to more accurately reflect human tumor type. The relevance of cervical cancer to trace element was studied in this paper. By means of quantitative trace element analysis in models and patients with cervical cancer, the tissue and serum levels of trace elements in papillomaviruses-induced cancer models were more similar to that of patients than the levels in models induced by HeLa cell and methylcholanthrene. The results reflect papillomaviruses model most accurately mimic in vivo carcinogenesis of patients with cervical cancer. It will have a superior predictive value over HeLa cell and methylcholanthrene models in pre-clinical trials. The papillomaviruses-induced cervical cancer can provide more reliable models for testing the efficacy of drugs in treating human cancers.     

Potential impact of antiretroviral therapy and screening on cervical cancer mortality in HIV-positive women in sub-Saharan Africa: a simulation

Background

Despite having high cervical cancer incidence and mortality rates, screening for cervical precancerous lesions remains infrequent in sub-Saharan Africa. The need to screen HIV-positive women because of the higher prevalence and faster progression of cervical precancerous lesions may be heightened by the increased access to highly-active antiretroviral therapy (HAART). Policymakers need quantitative data on the effect of HAART and screening to better allocate limited resources. Our aim was to quantify the potential effect of these interventions on cervical cancer mortality.

Methods and Findings

We constructed a Markov state-transition model of a cohort of HIV-positive women in Cameroon. Published data on the prevalence, progression and regression of lesions as well as mortality rates from HIV, cervical cancer and other causes were incorporated into the model. We examined the potential impact, on cumulative cervical cancer mortality, of four possible scenarios: no HAART and no screening (NHNS), HAART and no screening (HNS), HAART and screening once on HAART initiation (HSHI), and HAART and screening once at age 35 (HS35). Our model projected that, compared to NHNS, lifetime cumulative cervical cancer mortality approximately doubled with HNS. It will require 262 women being screened at HAART initiation to prevent one cervical cancer death amongst women on HAART. The magnitudes of these effects were most sensitive to the rate of progression of precancerous lesions.

Conclusions

Screening, even when done once, has the potential of reducing cervical cancer mortality among HIV-positive women in Africa. The most feasible and cost-effective screening strategy needs to be determined in each setting.     

人乳头瘤病毒（HPV）及其诱发子宫颈癌的新进展

子宫颈癌是一类发病率仅次于乳腺癌并严重危害女性生殖系统健康的最常见的妇科恶性肿瘤,在发展中国家,是女性癌症死亡的第一因素。自德国科学家哈拉尔德.楚尔豪森（Harald zur Hausen）因发现人乳头瘤病毒（Human papillomavirus,HPV）导致子宫颈癌而获得2008年度的诺贝尔生理学或医学奖后,全世界广泛认可人乳头瘤病毒（HPV）是引起子宫颈癌的最主要生物学因素。HPV病毒的持续感染在子宫颈癌的发生、发展过程中起了重要作用。本文就HPV病毒的生物学结构、女性生殖道HPV病毒的感染途径以及HPV病毒诱发子宫颈癌机制的最近的研究进展进行扼要综述。     

poly(I:C) synergizes with proteasome inhibitors to induce apoptosis in cervical cancer cells

Cervical cancer is one of the most common malignancies in women, with a poor survival rate. Thus, there is a need to define effective combination strategies to improve therapy. In this study, we report that dsRNA poly(I:C) up-regulated the expression of IFNβ and apoptosis-associated genes in cervical cancer cells, activating both intrinsic and extrinsic apoptotic pathways, and eventually inducing cell death. Similarly, proteasome inhibitors also effectively induced cervical cancer cell apoptosis, probably through prevention of p53 degradation, inhibiting NF-κB signal activation and decreasing BCL-2 expression. Importantly, the combination of poly(I:C) with proteasome inhibitors enhanced caspase-8 and caspase-9 activation, and synergistically induced cervical cancer cell apoptosis. Both activated p38 signals and increased ROS levels, and their combination extended these effects. Collectively, we show that the activation of multiple pro-apoptotic pathways by poly(I:C) and proteasome inhibitors underpin a synergistic effect on inducing cervical cancer cell death, suggesting a potential therapeutic combination with clinical relevance.     

高危型HPV和L1壳蛋白与宫颈病变关系的研究进展

宫颈病变是女性最常见的疾病之一,是多种因素共同作用的结果。宫颈癌及癌前病变的发生、发展是一个多因素、多步骤的复杂过程,多种基因的改变引发细胞的增殖失控。大量资料表明高危型人乳头瘤病毒(HPV)感染是宫颈病变的主要危险因素,其中HPV16、18型感染占了绝大部分。HPV整合状态与宫颈病变程度密切相关,人乳头瘤病毒(HPV)L1壳蛋白为免疫杀伤HPV病毒的主要靶位,L1蛋白的表达有利于激发人体细胞免疫,清除感染的细胞。HPV感染机体且病毒处于复制阶段时L蛋白才在机体中表达,但是当HPV病毒DNA与宿主细胞基因整合后,L1壳蛋白将不表达,无法形成一系列免疫反应,引发宫颈癌。HPV L1壳蛋白的表达缺失与宫颈病变的进展密切相关。本文对高危型HPV与HPV L1壳蛋白在宫颈病变中的研究进展作一综述。     

Interaction of C20-substituted derivative of pregnenolone acetate with copper (II) leads to ROS generation,DNA cleavage and apoptosis in cervical cancer cells: Therapeutic potential of copper chelation for cancer treatment

Cervical cancer is a leading cause of cancer-related deaths among women in developing countries. Therefore, development of new chemotherapeutic agents is required. Unlike normal cells, cancer cells contain elevated copper levels which play an integral role in angiogenesis. Thus, targeting copper via copper-specific chelators in cancer cells can serve as effective anticancer strategy. In this work, a copper chelator pregnenolone acetate nucleus-based tetrazole derivative (ligand-L) was synthesized and characterized by elemental analysis, ESI-MS, ¹H NMR and ¹³C NMR. DNA binding ability of ligand-L was studied using UV–Vis and fluorescence spectroscopy. Fluorescence spectroscopy studies reveal that quenching constant of ligand-l-DNA and ligand-L-Cu(II) were found to be 7.4 × 10³ M⁻¹ and 8.8 × 10³ M⁻¹, respectively. In vitro toxicity of ligand-L was studied on human cervical cancer C33A cancer cells. Results showed that ligand-L exhibit significant cytotoxic activity against cervical cancer C33A cells with IC₅₀ value 5.0 ± 1.8 µM. Further, it was found that ligand-L cytotoxicity is due to redox cycling of copper to generate ROS which leads to DNA damage and apoptosis. In conclusion, this is the report where we synthesized pregnenolone acetate-based tetrazole derivative against C33A cells that targets cellular copper to induce pro-oxidant death in cancer cells. These findings will provide significant insights into the development of new chemical molecules with better copper chelating and pro-oxidant properties against cancer cells.     

宫颈人乳头瘤病毒感染的药物治疗

宫颈癌是妇科三大恶性肿瘤之一。根据GLOBOCAN 2008数据统计,在中国女性所有恶性肿瘤中,发病比占6.3%,死亡比占4.6%。宫颈癌的发生与宫颈HPV感染存在密切关系。2012年NCCN指南提出30岁的女性推荐HPV DNA检查与细胞学检查结合用于宫颈癌的筛查。单纯HPV检测阳性时,患者可以选择继续观察随访。但事实上,妇科医生在临床诊疗过程中发现很多病人心理上无法接受对疾病不进行任何处理。而一些过度治疗方案包括LEEP,冷刀锥切,宫颈局部激光治疗等又有可能会造成宫颈机能不全,继发宫颈管狭窄,早产及低体重出生儿等不良结果。若积极处理的话有多种治疗方案可供选择。但是对于有生育要求的女性在治疗方案的选择上应该尤为慎重。本文对目前相关治疗方案的治疗效果及其能否阻止宫颈病变的进展等方面进行总结。旨在解决临床医生和患者共同关注的问题。     

Keratinocyte stem cells: Friends and foes

Skin and its appendages provide a protective barrier against the assaults of the environment. To perform its role, epidermis undergoes an ongoing renewal through a balance of proliferation and differentiation/apoptosis called homeostasis. Keratinocyte stem cells reside in a special microenvironment called niche in basal epidermis, adult hair follicle, and sebaceous glands. While a definite marker has yet to be detected, data raised part in humans and part in the mouse system point to a critical role of stem and its progeny transit amplifying cells in epidermal homeostasis. Stem cells are protected from apoptosis and are long resident in adult epidermis. This renders them more prone to be the origin of skin cancer. In this review, we will outline the main features of adult stem cells in mouse and humans and discuss their fate in relation to differentiation, apoptosis, and cancer. J. Cell. Physiol. 225: 310–315, 2010. © 2010 Wiley‐Liss, Inc.     

Induction of apoptosis by casticin in cervical cancer cells: reactive oxygen species-dependent sustained activation of Jun N-terminal kinase

Casticin, a polymethoxyflavone from Fructus viticis used as an anti-inflammatory agent in Chinese traditional medicine, has been reported to have anti-cancer activity. The purpose of this study was to examine the apoptotic activity of casticin on human cervical cancer cells and its molecular mechanism. We revealed a novel mechanism by which casticin-induced apoptosis occurs and showed for the first time that the apoptosis induced by casticin is mediated through generation of reactive oxygen species (ROS) and sustained activation of c-Jun N-terminal kinase (JNK) in HeLa cells. Casticin markedly increased the levels of intracellular ROS and induced the expression of phosphorylated JNK and c-Jun protein. Pre-treatment with N-acetylcysteine and SP600125 effectively attenuated induction of apoptosis by casticin in HeLa cells. Moreover, casticin induced ROS production and apoptotic cell death in other cervical cancer cell lines, such as CasKi and SiHa. Importantly, casticin did not cause generation of ROS or induction of apoptosis in normal human peripheral blood mononuclear cells and embryonic kidney epithelium 293 cells. These results suggest that ROS generation and sustained JNK activation by casticin play a role in casticin-induced apoptosis and raise the possibility that treatment with casticin might be promising as a new therapy against human cervical cancer.     

Proteomic analysis reveals tanshinone IIA enhances apoptosis of advanced cervix carcinoma CaSki cells through mitochondria intrinsic and endoplasmic reticulum stress pathways

Cervix cancer is the second most common cancer among women worldwide, whereas paclitaxel, the first line chemotherapeutic drug used to treat cervical cancer, shows low chemosensitivity on the advanced cervical cancer cell line. Tanshinone IIA (Tan IIA) exhibited strong growth inhibitory effect on CaSki cells (IC₅₀ = 5.51 μM) through promoting caspase cascades with concomitant upregulating the phosphorylation of p38 and JNK signaling. Comprehensive proteomics revealed the global protein changes and the network analysis implied that Tan IIA treatment would activate ER stress pathways that finally lead to apoptotic cell death. Moreover, ER stress inhibitor could alleviate Tan IIA caused cell growth inhibition and ameliorate C/EBP‐homologous protein as well as apoptosis signal‐regulating kinase 1 mediated cell death. The therapeutic interventions targeting the mitochondrial‐related apoptosis and ER stress responses might be promising strategies to conquer paclitaxel resistance.     

Folate deficiency, mismatch repair-dependent apoptosis, and human disease

The vitamin that is most commonly deficient in the American diet is folate. Severe folate deficiency in humans is known to cause megaloblastic anemia and developmental defects, and is associated with an increased incidence of several forms of human cancer. Although the exact mechanisms by which this vitamin deficiency may cause these diseases are not known at the present time, recent work has shown that folate deficiency also causes genomic instability and programmed cell death (or apoptosis). Additionally, it is known that the DNA mismatch repair pathway mediates folate deficiency-induced apoptosis. This review will first describe work suggesting that folate deficiency causes genomic instability and apoptosis, then discuss possible mechanisms by which the mismatch repair pathway could trigger folate deficiency-induced apoptosis, which has either protective or destructive effects on tissue.     

Nelfinavir, a new anti-cancer drug with pleiotropic effects and many paths to autophagy

The development of cancer drugs is slow and costly. One approach to accelerate the availability of new drugs is to reposition drugs approved for other indications as anti-cancer agents. HIV protease inhibitors (HIV PIs) are useful in treating HIV infection and cause toxicities in humans that are similar to those observed when the kinase Akt, a target for cancer therapy, is inhibited. To test whether HIV PIs inhibited Akt and cancer cell proliferation, we screened 6 HIV PIs and found that three, ritonavir, saquinavir and nelfinavir, inhibit the growth of over 60 cancer cell lines derived from 9 different tumor types; Nelfinavir is the most potent. Nelfinavir causes caspase-dependent apoptosis and non-apoptotic death, as well as endoplasmic reticulum (ER) stress and autophagy. Nelfinavir blocks growth factor receptor activation and decreases growth factor-induced and endogenous Akt signaling. In vivo, nelfinavir inhibits tumor growth and upregulates markers of ER stress, autophagy and apoptosis. Nelfinavir is currently being tested in cancer patients in Phase I clinical trials where biomarkers will be assessed. Current studies are focused on measuring autophagy in clinical specimens and identifying combination strategies that will exploit the induction of autophagy and increase the effectiveness of nelfinavir.     

miRNAs表达异常与宫颈癌发生发展关系的研究进展

宫颈癌(cervical cancer,CC)是严重危害女性健康的疾病之一,具有高的发病率和死亡率。微小RNA(miRNAs)是一类小分子非编码RNA,通过转录后沉默来调控基因表达。表达异常的miRNAs主要通过调控细胞周期、细胞凋亡以及多种信号通路的方式参与宫颈癌的发生发展。该文就近年来miRNAs在宫颈癌发生发展、诊断、治疗和预后评估等方面的研究进展做一综述,以寻求对宫颈癌的防治提供新思路。     

Nelfinavir,a new anti-cancer drug with pleiotropic effects and many paths to autophagy

The development of cancer drugs is slow and costly. One approach to accelerate the availability of new drugs is to reposition drugs approved for other indications as anti-cancer agents. HIV protease inhibitors (HIV PIs) are useful in treating HIV infection and cause toxicities in humans that are similar to those observed when the kinase Akt, a target for cancer therapy, is inhibited. To test whether HIV PIs inhibited Akt and cancer cell proliferation, we screened 6 HIV PIs and found that three, ritonavir, saquinavir and nelfinavir, inhibit the growth of over 60 cancer cell lines derived from 9 different tumor types; Nelfinavir is the most potent. Nelfinavir causes caspase-dependent apoptosis and non-apoptotic death, as well as endoplasmic reticulum (ER) stress and autophagy. Nelfinavir blocks growth factor receptor activation and decreases growth factor-induced and endogenous Akt signaling. In vivo, nelfinavir inhibits tumor growth and upregulates markers of ER stress, autophagy and apoptosis. Nelfinavir is currently being tested in cancer patients in Phase I clinical trials where biomarkers will be assessed. Current studies are focused on measuring autophagy in clinical specimens and identifying combination strategies that will exploit the induction of autophagy and increase the effectiveness of nelfinavir.     

Human bone marrow mesenchymal stem cell-derived extracellular vesicles impede the progression of cervical cancer via the miR-144-3p/CEP55 pathway

Cervical cancer is the most common gynaecological malignancy, with a high incidence rate and mortality rate in middle-aged women. Human bone marrow mesenchymal stem cells (hBMSCs) have been implicated in the initiation and subsequent development of cancer, along with the involvement of extracellular vesicles (EVs) mediating intracellular communication by delivering microRNAs (miRNAs or miRs). This study is aimed at investigating the physiological mechanisms by which EVs-encapsulated miR-144-3p derived from hBMSCs might mediate the progression of cervical cancer. The expression profiles of centrosomal protein, 55 Kd (CEP55) and miR-144-3p in cervical cancer cell lines and tissues, were quantified by RT-qPCR and Western blot analysis. The binding affinity between miR-144-3p and CEP55 was identified using in silico analysis and luciferase activity determination. Cervical cancer cells were co-cultured with EVs derived from hBMSCs that were treated with either miR-144-3p mimic or miR-144-3p inhibitor. Cervical cancer cell proliferation, invasion, migration and apoptosis were detected in vitro. The effects of hBMSCs-miR-144-3p on tumour growth were also investigated in vivo. miR-144-3p was down-regulated, whereas CEP55 was up-regulated in cervical cancer cell lines and tissues. CEP55 was targeted by miR-144-3p, which suppressed cervical cancer cell proliferation, invasion and migration and promoted apoptosis via CEP55. Furthermore, similar results were obtained by hBMSCs-derived EVs carrying miR-144-3p. In vivo assays confirmed the tumour-suppressive effects of miR-144-3p in hBMSCs-derived EVs on cervical cancer. Collectively, hBMSCs-derived EVs-loaded miR-144-3p impedes the development and progression of cervical cancer through target inhibition of CEP55, therefore providing us with a potential therapeutic target for treating cervical cancer.