In vivo reduction of RAD51-mediated homologous recombination triggers aging but impairs oncogenesis.

Homologous recombination (HR) is a prominent DNA repair pathway maintaining genome integrity. Mutations in many HR genes lead to cancer predisposition. Paradoxically, the implication of the pivotal HR factor RAD51 on cancer development remains puzzling. Particularly, no RAD51 mouse models are available to address the role of RAD51 in aging and carcinogenesis in vivo. We engineered a mouse model with an inducible dominant-negative form of RAD51 (SMRad51) that suppresses RAD51-mediated HR without stimulating alternative mutagenic repair pathways. We found that in vivo expression of SMRad51 led to replicative stress, systemic inflammation, progenitor exhaustion, premature aging and reduced lifespan, but did not trigger tumorigenesis. Expressing SMRAD51 in a breast cancer predisposition mouse model (PyMT) decreased the number and the size of tumors, revealing an anti-tumor activity of SMRAD51. We propose that these in vivo phenotypes result from chronic endogenous replication stress caused by HR decrease, which preferentially targets progenitors and tumor cells. Our work underlines the importance of RAD51 activity for progenitor cell homeostasis, preventing aging and more generally for the balance between cancer and aging.

Cluster of differentiation 44 promotes osteosarcoma progression in mice lacking the tumor suppressor Merlin.

Merlin is a versatile tumor suppressor protein encoded by the NF2 gene. Several lines of evidence suggest that Merlin exerts its tumor suppressor activity, at least in part, by forming an inhibitory complex with cluster of differentiation 44 (CD44). Consistently, numerous NF2 mutations in cancer patients are predicted to perturb the interaction of Merlin with CD44. We hypothesized that disruption of the Merlin-CD44 complex through loss of Merlin, unleashes putative tumor- or metastasis-promoting functions of CD44. To evaluate the relevance of the Merlin-CD44 interaction in vivo, we compared tumor growth and progression in Cd44-positive and Cd44-negative Nf2-mutant mice. Heterozygous Nf2-mutant mice were prone to developing highly metastatic osteosarcomas. Importantly, while the absence of the Cd44 gene had no effect on the frequency of primary osteosarcoma development, it strongly diminished osteosarcoma metastasis formation in the Nf2-mutant mice. In vitro assays identified transendothelial migration as the most prominent cellular phenotype dependent on CD44. Adhesion to endothelial cells was blocked by interfering with integrin α4ß1 (very late antigen-4, VLA-4) on osteosarcoma cells and CD44 upregulated levels of integrin VLA-4 ß1 subunit. Among other putative functions of CD44, which may contribute to the metastatic behavior, the passage through the endothelial cells also appears to be critical in vivo, as CD44 significantly promoted formation of lung metastasis upon intravenous injection of osteosarcoma cells into immunocompromised mice. Altogether, our results strongly suggest that CD44 plays a metastasis-promoting role in the absence of Merlin.

Correlation Between p16/Ki-67 Expression and the Grade of Cervical Intraepithelial Neoplasias.

Interpretation of histopathology of cervical premalignant lesions suffers from marked interobserver variability due to its subjective nature. We aimed to evaluate the usefulness of the biomarkers p16 and Ki-67 in improving the diagnostic accuracy of cervical histopathology and assess the correlation between p16 expression and human papillomavirus test in different grades of cervical intraepithelial neoplasia (CIN). Cervical tissue specimens with a diagnosis of CIN 1 or worse (CIN 1+) on hematoxylin and eosin staining were selected for immunohistochemistry (IHC) staining for p16 and Ki-67. The IHC slides were examined by a gynecologic pathologist along with a review of hematoxylin and eosin slides. The review histopathology diagnosis was used to correlate with the IHC results. We observed that the proportion of women with overexpression of p16 increased with increasing histologic severity: 0% in women with normal histology; 33.3% in women with CIN 1; 58.1% in women with CIN 2; and 73.8% in women with CIN 3. Among the human papillomavirus-positive women, 76.3% (58/76) women with CIN 2/CIN 3 expressed p16, and only 8.9% (4/45) women with normal histopathology or CIN 1 expressed the same. A combination of p16 positivity and abnormal expression of Ki-67 beyond the lower third of the epithelium was observed in 0% of normal/CIN 1 and 60.5% (40/66) of CIN 3 detected on routine histopathology. We concluded that dual staining could be used as an adjunctive test to improve the diagnostic accuracy of histopathology. In addition, p16/Ki-67 IHC has a role in guiding management decisions in cases with discordant colposcopy and histopathology diagnoses.

cd44 deletion suppresses atypia in the precancerous mouse testis.

Loss-of-function of RHAMM causes hypofertility and testicular atrophy in young mice, followed by germ cell neoplasia in situ (GCNIS) of the testis, cellular atypia, and development of the testicular germ cell tumor (TGCT) seminoma. These pathologies reflect the risk factors and phenotypes that precede seminoma development in humans and-given the high prevalence of RHAMM downregulation in human seminoma-link RHAMM dysfunction with the aetiology of male hypofertility and GCNIS-related TGCTs. The initiating event underlying these pathologies, in RHAMM mutant testis, is premature displacement of undifferentiated progenitors from the basal compartment. We hypothesized that cd44 (both cancer initiating cell- and oncogenic progression marker) will drive GCNIS development, induced by RHAMM-loss-of-function in the mouse. We report that cd44 is expressed in a specific subset of GCNIS testes. Its genetic deletion has no effect on GCNIS onset, but it ameliorates oncogenic progression. We conclude that cd44 expression, combined with RHAMM dysfunction, promotes oncogenic progression in the testis.

Glucocorticoid receptor in stromal cells is essential for glucocorticoid-mediated suppression of inflammation in arthritis.

BACKGROUND: Glucocorticoid (GC) therapy is frequently used to treat rheumatoid arthritis due to potent anti-inflammatory actions of GCs. Direct actions of GCs on immune cells were suggested to suppress inflammation. OBJECTIVES: Define the role of the glucocorticoid receptor (GR) in stromal cells for suppression of inflammatory arthritis. METHODS: Bone marrow chimeric mice lacking the GR in the hematopoietic or stromal compartment, respectively, and mice with impaired GR dimerisation (GRdim) were analysed for their response to dexamethasone (DEX, 1 mg/kg) treatment in serum transfer-induced arthritis (STIA). Joint swelling, cell infiltration (histology), cytokines, cell composition (flow cytometry) and gene expression were analysed and RNASeq of wild type and GRdim primary murine fibroblast-like synoviocytes (FLS) was performed. RESULTS: GR deficiency in immune cells did not impair GC-mediated suppression of STIA. In contrast, mice with GR-deficient or GR dimerisation-impaired stromal cells were resistant to GC treatment, despite efficient suppression of cytokines. Intriguingly, in mice with impaired GR function in the stromal compartment, GCs failed to stimulate non-classical, non-activated macrophages (Ly6Cneg, MHCIIneg) and associated anti-inflammatory markers CD163, CD36, AnxA1, MerTK and Axl. Mice with GR deficiency in FLS were partially resistant to GC-induced suppression of STIA. Accordingly, RNASeq analysis of DEX-treated GRdim FLS revealed a distinct gene signature indicating enhanced activity and a failure to reduce macrophage inflammatory protein (Mip)-1α and Mip-1ß. CONCLUSION: We report a novel anti-inflammatory mechanism of GC action that involves GR dimerisation-dependent gene regulation in non-immune stromal cells, presumably FLS. FLS control non-classical, anti-inflammatory polarisation of macrophages that contributes to suppression of inflammation in arthritis.

High incidence of mammary intraepithelial neoplasia development in Men1-disrupted murine mammary glands.

Mutations of the MEN1 tumour suppressor gene predispose patients to the development of multiple endocrine neoplasia type 1 (MEN1) syndrome, which is characterized by multiple endocrine tumours, including prolactinomas. The recent findings of the interaction between menin, encoded by the MEN1 gene, and the oestrogen receptor, as well as the observation of rare cases of mammary carcinomas in our heterozygous Men1 mutant mice, led us to investigate a putative tumour suppressor function of the Men1 gene in mouse mammary cells by disrupting the gene in luminal epithelial cells. A significantly higher incidence of mammary intraepithelial neoplasia (MIN) was observed in mutant WapCre-Men1(F/F) mice (51.5%) than in WapCre-Men1(+/+) (0%) or Men1(F/F) (7.1%) control mice. The majority of MIN observed in the mutant mice displayed complete menin inactivation. Because of the leakage of WapCre transgene expression, prolactinomas were observed in 83.3% of mutant mice, leading to premature death. As there was no correlation between MIN development and elevated serum prolactin levels, and phospho-STAT5 expression was decreased in mammary lesions, the increased incidence of MIN lesions was most likely due to Men1 disruption rather than to prolactinoma development. Interestingly, in MIN lesions, we found a decrease in membrane-associated E-cadherin and beta-catenin expression, the latter of which is a menin partner. Finally, reduced menin expression was found in a large proportion of two independent cohorts of patients with breast carcinomas. Taken together, the current work indicates a role of Men1 inactivation in the development of mammary pre-cancerous lesions in mice and a potential role in human mammary cancer.

Glucocorticoid therapy of antigen-induced arthritis depends on the dimerized glucocorticoid receptor in T cells.

Despite several side effects, glucocorticoids (GCs) have been widely used for 60 y to treat rheumatoid arthritis on the basis of their antiinflammatory effects. However, the cells targeted by GCs and the transcriptional mechanisms underlying their actions through the glucocorticoid receptor (GR) in steroid therapy remain poorly defined. Using cell type-specific GR-deficient mice subjected to antigen-induced arthritis (AIA) as a model of human rheumatoid arthritis, we show that GC action on T cells but not myeloid cells is critical for therapeutic intervention in AIA. Furthermore, the resistance of mice expressing a DNA binding-defective GR (GR(dim)) to GC treatment reveals that dimerization of the GR is indispensable for the antiinflammatory effects. In these mice, the GC-induced suppression of T(H)1 and T(H)17 cell-derived proinflammatory cytokines is impaired. Our finding that IL-17A(-/-) mice are resistant to GC therapy, whereas IFN-γ(-/-) mice respond as efficiently as WT mice implies that IL-17-producing T cells and not IFN-γ-producing T cells are the most important targets for an efficient GC therapy. The present study's identification of the critical cell type and the mode of GR action in steroid therapy of AIA significantly advances our understanding of steroid therapy and should lead to therapies with greater efficiency and fewer side effects.

Hepatic induction of cholesterol biosynthesis reflects a remote adaptive response to pneumococcal pneumonia.

Community-acquired pneumonia presents a spectrum of clinical phenotypes, from lobar pneumonia to septic shock, while mechanisms underlying progression are incompletely understood. In a transcriptomic and metabolomic study across tissues, we examined serotype-specific regulation of signaling and metabolic pathways in C57BL/6 mice intratracheally instilled with either serotype 19F Streptococcus pneumoniae (S19; causing lobar pneumonia), or serotype 2 S. pneumoniae (S2; causing septic pneumococcal disease,) or vehicle (Todd-Hewitt broth). Samples of lung, liver, and blood were collected at 6 and 24 h postinfection and subjected to microarray analysis and mass spectrometry. Results comprise a preferential induction of cholesterol biosynthesis in lobar pneumonia at low-infection doses (10(5) colony forming units/mouse) leading to increased plasma cholesterol (vehicle: 1.8±0.12 mM, S2: 2.3±0.10 mM, S19: 2.9±0.15 mM; P<0.05, comparing S19 to vehicle and S2). This induction was pneumolysin dependent, as a pneumolysin-deficient strain of serotype 19F failed to induce cholesterol biosynthesis (S19ΔPLY: 1.9±0.03 mM). Preincubation of pneumolysin with purified cholesterol or plasma from hypercholesterolemic mice prior to intratracheal instillation protected against lung barrier dysfunction and alveolar macrophage necrosis. Cholesterol may attenuate disease severity by neutralizing pneumolysin in the alveolar compartment and thus prevent septic disease progression.

Contribution of referent pathologists to the quality of trophoblastic diseases diagnosis.

OBJECTIVE: To evaluate the contribution of referent pathologists (RPs) to the quality of diagnosis of trophoblastic diseases and to study the level of diagnostic agreement between the initial pathologists and the RPs. METHODS: This observational retrospective study was carried between 1 November 1999 and 11 January 2011 using the database of the French Trophoblastic Disease Reference Centre in Lyon. All files for hydatiform moles (HMs), trophoblastic tumours and non-molar pregnancies for which there was an initial suspicion of trophoblastic disease were included, whenever there was rereading of the slides by an RP. A total of 1851 HMs and 150 gestational trophoblastic tumours were analysed. RESULTS: When the initial pathologist diagnosed a complete mole, the RP confirmed the diagnosis in 96% of cases. When the initial pathologist diagnosed a partial mole, the RP confirmed the diagnosis in only 64% of cases. For trophoblastic tumours, when the initial pathologist diagnosed a choriocarcinoma, the RP confirmed the diagnosis in 86% of cases. When the initial anatomopathology suggested an invasive mole, the diagnosis was confirmed in 96% of cases. Finally, when the initial diagnosis was a placental site trophoblastic tumour or an epithelioid trophoblastic tumour, the RP confirmed the diagnosis in 60 and 100% of cases, respectively. CONCLUSION: A systematic policy of rereading of slides for all suspicious moles improves the quality of management of trophoblastic diseases at a national level.

TRIP6 functions in brain ciliogenesis.

TRIP6, a member of the ZYXIN-family of LIM domain proteins, is a focal adhesion component. Trip6 deletion in the mouse, reported here, reveals a function in the brain: ependymal and choroid plexus epithelial cells are carrying, unexpectedly, fewer and shorter cilia, are poorly differentiated, and the mice develop hydrocephalus. TRIP6 carries numerous protein interaction domains and its functions require homodimerization. Indeed, TRIP6 disruption in vitro (in a choroid plexus epithelial cell line), via RNAi or inhibition of its homodimerization, confirms its function in ciliogenesis. Using super-resolution microscopy, we demonstrate TRIP6 localization at the pericentriolar material and along the ciliary axoneme. The requirement for homodimerization which doubles its interaction sites, its punctate localization along the axoneme, and its co-localization with other cilia components suggest a scaffold/co-transporter function for TRIP6 in cilia. Thus, this work uncovers an essential role of a LIM-domain protein assembly factor in mammalian ciliogenesis.

Characterisation of prostate cancer lesions in heterozygous Men1 mutant mice.

BACKGROUND: Mutations of the MEN1 gene predispose to multiple endocrine neoplasia type 1 (MEN1) syndrome. Our group and others have shown that Men1 disruption in mice recapitulates MEN1 pathology. Intriguingly, rare lesions in hormone-dependent tissues, such as prostate and mammary glands, were also observed in the Men1 mutant mice. METHODS: To study the occurrence of prostate lesions, we followed a male mouse cohort of 47 Men1+/- mice and 23 age-matched control littermates, starting at 18 months of age, and analysed the prostate glands from the cohort. RESULTS: Six Men1+/- mice (12.8%) developed prostate cancer, including two adenocarcinomas and four in situ carcinomas, while none of the control mice developed cancerous lesions. The expression of menin encoded by the Men1 gene was found to be drastically reduced in all carcinomas, and partial LOH of the wild-type Men1 allele was detected in three of the five analysed lesions. Using immunostaining for the androgen receptor and p63, a basal epithelial cell marker, we demonstrated that the menin-negative prostate cancer cells did not display p63 expression and that the androgen receptor was expressed but more heterogeneous in these lesions. Furthermore, our data showed that the expression of the cyclin-dependent kinase inhibitor CDKN1B (p27), a Men1 target gene known to be inactivated during prostate cell tumorigenesis, was notably decreased in the prostate cancers that developed in the mutant mice. CONCLUSION: Our work suggests the possible involvement of Men1 inactivation in the tumorigenesis of the prostate gland.

[Prevalence of HPV infection in precancerous and cancerous lesions of the uterine cervix in Tunisia]. / Prévalence des infections à papillomavirus (HPV) dans les lésions précancéreuses et cancéreuses du col utérin en Tunisie.

OBJECTIVES: To investigate the distribution of HPV genotypes inuterine cervical lesions in Central Tunisia in order to predict the impact ofHPV vaccines and HPV-based screening tests among Tunisian women. MATERIAL AND METHODS: We performed a retrospective study of 146 fixed tissues including 30 benign lesions, 36 low-grade cervical intraepithelial neoplasias (CIN1), 45 high-grade cervical intraepithelial neoplasias (CIN2/3), 26 invasive squamous cell carcinomas (SCC) and 9 adenocarcinomas. HPV infection detection and typing were investigated by PCR technique using consensus GP5/GP6 primers and type specific primers for HPV6/11, 16, 18, 31 and 33. RESULTS: Among our patients, overall HPV prevalence was 73.6% (p = 0.0001). HPV infection was associated to 84% of precancerous lesions and 83.9% of cancers. High-risk HPV infection (HPV16 and 18) was detected in 17.4% of CIN1, 74.3% of CIN2/3 (p = 0.002) and 73.1% of cancers (p = 0.001). HPV16 was the most common type among CIN2/3 (51.2%, p < 0.001), invasive SCC (47.6%, p = 0.001) and adenocarcinomas (80%, p < 0.001). CONCLUSION: This study supports previous population-based studies in which similar HPV detection rates were found among random samples of women. HPV-based screening tests and HPV vaccination would be efficient in uterine cervix cancer prevention among women in the Central Tunisia.

[p16INK4A overexpression is a useful marker for uterine cervix lesions]. / La surexpression de p16 INK4A est un marqueur utile des lésions du col utérin.

The histological criteria of uterine cervix lesions are well known. However, there is a poor diagnostic reproducibility especially concerning low-grade precancerous lesions. Therefore, the aim of our study was to evaluate the utility of p16INK4A overexpression as a surrogate biomarker of precancerous lesions of the uterine cervix. A retrospective study was carried out by the International Center for Research on Cancer, Lyon, on 79 uterine cervix lesions. Specimens included 4 normal tissue samples, 24 benign lesions, 9 low-grade precancerous lesions (CIN1), 40 high-grade precancerous lesions (CIN2-3) and 2 squamous cell carcinomas. Immunohistochemistry was used to find p16INK4A expression. HPV infection was detected by HPV testing. No p16INK4A expression was detected in normal tissues and benign lesions of the uterine cervix. p16INK4A immunolabeling was weak in CIN1 cases (77.8%). Strong and diffuse p16INK4A expression was detected among all precancerous lesions (CIN2-3) and squamous cell carcinomas. p16INK4A overexpression was associated to the CIN grade (p<0.0001) and high-risk HPV infection (p<0.0001). In conclusion, p16INK4A overexpression should be regarded as a surrogate biomarker of precancerous lesions of the uterine cervix. p16INK4A overexpression is useful in reducing the variability during evaluation of suspicious biopsies of the uterine cervix.

A novel function of DNA repair molecule Nbs1 in terminal differentiation of the lens fibre cells and cataractogenesis.

The Nbs1 protein, hypomorphic mutant in Nijmegen breakage syndrome (NBS), is a component of the Mre11/Rad50/Nbs1 (M/R/N) complex that acts as a DNA double-strand break sensor and functions in cell cycle checkpoint in response to DNA damage and DNA repair. Here we report that targeted disruption of murine NBS1 gene (Nbn) in the lens alters the M/R/N complex nuclear localization and results in microphthalmia in mice due to reduced proliferation of the lens epithelial cells. Unexpectedly, all Nbn-deficient lenses develop cataracts at an early age due to altered lens fibre cell differentiation, including disruption of normal lens epithelial and fibre cell architecture and incomplete denucleation of fibre cells, and these changes are independent of the p53 pathway. In addition, Nbn-deficient lenses show dysregulated transcription of various crystallins. Thus, this study implicates a novel function of Nbs1 in terminal differentiation of the lens fibre cells and in cataractogenesis.

First epidemiological data from the French Trophoblastic Disease Reference Center.

OBJECTIVE: The objective of the study was to describe women registered at the new French Trophoblastic Disease Reference Center and particularly the rates of gestational trophoblastic neoplasia (GTN) after molar pregnancies. STUDY DESIGN: Epidemiological data from a prospective cohort of women registered between November 1999 and November 2004 were analyzed. RESULTS: Four hundred forty-eight women were registered. The referent pathologist reclassified 32% and 5% of assumed partial mole (PM) and complete mole (CM), respectively. GTN developed in 30 of 212 patients with singleton CM (14%) and in 5 of 108 with singleton PM (5%). Among 131 patients with GTN (35 women followed up after registration for a mole and 96 registered for a GTN), 115 (88%) were low-risk and 16 (12%) were high-risk patients according to 2000 International Federation of Gynecology and Obstetrics (FIGO) scoring system. CONCLUSION: Creation of trophoblastic disease reference centers is desirable to improve treatment of patients. Our results will have to be compared with future publications based on the new 2000 FIGO oncology committee recommendations.

Analysis of genetic variants of the poly(ADP-ribose) polymerase-1 gene in breast cancer in French patients.

Poly(ADP-ribose) polymerase-1 (PARP-1) is a nuclear enzyme that catalyzes the poly(ADP-ribosyl)ation of target proteins in response to DNA damage and has been proposed to play a role in DNA repair, recombination, transcription, cell death, cell proliferation, as well as in stabilization of the genome. We have recently shown that PARP-1 deficiency causes mammary tumorigenesis in mice. In the present study, we investigated whether genetic variants and single nucleotide polymorphisms (SNPs) of PARP-1 contribute to human breast cancer. To this end, we screened all PARP-1 exons, 7.1kb of intron-exon junction and 1.0-kb promoter sequences in 83 French patients with breast cancer and 100 controls by direct sequencing of genomic DNA. Twenty rare genetic variants of PARP-1, including c.1148C>A (Ser383Tyr), c.1354C>A (Arg452Arg), c.2819A>G (Lys940Arg) were detected in nine (10.8%) breast cancers of these patients. Among 31 polymorphic sites examined, five haplotype-tagging SNPs (htSNPs) of PARP-1 were identified. Interestingly, the genotype distribution of htSNP c.852T>C (Ala284Ala) was likely associated with loss of estrogen- and progesterone-receptor expression. The present study implies that genetic variants of PARP-1 may contribute to breast cancerogenesis and that PARP-1 htSNP c.852T>C (Ala284Ala) may influence hormonal therapy of breast cancer.

Spindle Misorientation of Cerebral and Cerebellar Progenitors Is a Mechanistic Cause of Megalencephaly.

Misoriented division of neuroprogenitors, by loss-of-function studies of centrosome or spindle components, has been linked to the developmental brain defects microcephaly and lissencephaly. As these approaches also affect centrosome biogenesis, spindle assembly, or cell-cycle progression, the resulting pathologies cannot be attributed solely to spindle misorientation. To address this issue, we employed a truncation of the spindle-orienting protein RHAMM. This truncation of the RHAMM centrosome-targeting domain does not have an impact on centrosome biogenesis or on spindle assembly in vivo. The RHAMM mutants exhibit misorientation of the division plane of neuroprogenitors, without affecting the division rate of these cells, resulting against expectation in megalencephaly associated with cerebral cortex thickening, cerebellum enlargement, and premature cerebellum differentiation. We conclude that RHAMM associates with the spindle of neuroprogenitor cells via its centrosome-targeting domain, where it regulates differentiation in the developing brain by orienting the spindle.

HMMR acts in the PLK1-dependent spindle positioning pathway and supports neural development.

Oriented cell division is one mechanism progenitor cells use during development and to maintain tissue homeostasis. Common to most cell types is the asymmetric establishment and regulation of cortical NuMA-dynein complexes that position the mitotic spindle. Here, we discover that HMMR acts at centrosomes in a PLK1-dependent pathway that locates active Ran and modulates the cortical localization of NuMA-dynein complexes to correct mispositioned spindles. This pathway was discovered through the creation and analysis of Hmmr-knockout mice, which suffer neonatal lethality with defective neural development and pleiotropic phenotypes in multiple tissues. HMMR over-expression in immortalized cancer cells induces phenotypes consistent with an increase in active Ran including defects in spindle orientation. These data identify an essential role for HMMR in the PLK1-dependent regulatory pathway that orients progenitor cell division and supports neural development.

p16INK4A overexpression and HPV infection in uterine cervix adenocarcinoma.

Human papillomaviruses (HPVs) are causally involved in the genesis of cervical carcinomas and their precursors, and there is a strong relationship between the cyclin-dependant kinase inhibitor p16INK4A and HPV infection. This study was carried out to assess the correlations between p16INK4A expression as an early biomarker of the endocervical adenocarcinoma and HPV infection. p16INK4A expression and HPV typing were performed on 46 samples including 5 normal endocervix, 9 benign lesions of the endocervix, 25 endocervical adenocarcinomas, and 7 endometrioid adenocarcinomas of the uterine corpus. A semiquantification of the p16INK4A immunostaining was realized (using both the staining intensity and the percentage of positive cells) and was graded from 0 to 15. All of the 25 endocervical adenocarcinomas overexpressed p16INK4A; the adjacent epithelium and the connective tissue were strictly negative. No p16INK4A was detected in nine benign endocervical lesions and in five normal endocervix. Few endometrioid adenocarcinomas of the uterine corpus that infiltrate the endocervix exhibited a low immunoreactivity (score 0/15 or 1/15). This pattern of expression is significantly associated with HPV infection (p<10(-3)), mainly high-risk HPV types (p=0.02). Our results suggest that p16INK4A is a putative molecular biomarker that consistently discriminates uterine cervix adenocarcinomas from benign lesions and from endometrioid adenocarcinomas of the uterine corpus.