Cell shape sensing licenses dendritic cells for homeostatic migration to lymph nodes.

Immune cells experience large cell shape changes during environmental patrolling because of the physical constraints that they encounter while migrating through tissues. These cells can adapt to such deformation events using dedicated shape-sensing pathways. However, how shape sensing affects immune cell function is mostly unknown. Here, we identify a shape-sensing mechanism that increases the expression of the chemokine receptor CCR7 and guides dendritic cell migration from peripheral tissues to lymph nodes at steady state. This mechanism relies on the lipid metabolism enzyme cPLA2, requires nuclear envelope tensioning and is finely tuned by the ARP2/3 actin nucleation complex. We also show that this shape-sensing axis reprograms dendritic cell transcription by activating an IKKß-NF-κB-dependent pathway known to control their tolerogenic potential. These results indicate that cell shape changes experienced by immune cells can define their migratory behavior and immunoregulatory properties and reveal a contribution of the physical properties of tissues to adaptive immunity.

Neutrophils drive type I interferon production and autoantibodies in patients with Wiskott-Aldrich syndrome.

BACKGROUND: Wiskott-Aldrich syndrome (WAS) is a rare primary immunodeficiency caused by mutations in Wiskott-Aldrich syndrome protein (WASp), a key regulator of cytoskeletal dynamics in hematopoietic cells. A high proportion of patients experience autoimmunity caused by a breakdown in T- and B-cell tolerance. Moreover, excessive production of type I interferon (IFN-I) by plasmacytoid dendritic cells (pDCs) contributes to autoimmune signs; however, the factors that trigger excessive innate activation have not been defined. OBJECTIVE: Neutrophil extracellular traps (NETs) emerged as major initiating factors in patients with diseases such as systemic lupus erythematosus and rheumatoid arthritis. In this study we explored the possible involvement of aberrant neutrophil functions in patients with WAS. METHODS: We evaluated the expression of a set of granulocyte genes associated with NETs in a cohort of patients with WAS and the presence of NET inducers in sera. Using a mouse model of WAS, we analyzed NET release by WASp-null neutrophils and evaluated the composition and homeostasis of neutrophils in vivo. By using depletion experiments, we assessed the effect of neutrophils in promoting inflammation and reactivity against autoantigens. RESULTS: Transcripts of genes encoding neutrophil enzymes and antimicrobial peptides were increased in granulocytes of patients with WAS, and serum-soluble factors triggered NET release. WASp-null neutrophils showed increased spontaneous NETosis, induced IFN-I production by pDCs, and activated B cells through B-cell activating factor. Consistently, their depletion abolished constitutive pDC activation, normalized circulating IFN-I levels, and, importantly, abolished production of autoantibodies directed against double-stranded DNA, nucleosomes, and myeloperoxidase. CONCLUSIONS: These findings reveal that neutrophils are involved in the pathogenic loop that causes excessive activation of innate cells and autoreactive B cells, thus identifying novel mechanisms that contribute to the autoimmunity of WAS.

ALCAM-mediated cDC1 CD8 T cells interactions are suppressed in advanced lung tumors.

Conventional type 1 dendritic cells (cDC1) are critical regulators of anti-tumoral T-cell responses. The structure and abundance of intercellular contacts between cDC1 and CD8 T cells in cancer tissues is important to determine the outcome of the T-cell response. However, the molecular determinants controlling the stability of cDC1-CD8 interactions during cancer progression remain poorly investigated. Here, we generated a genetic model of non-small cell lung cancer crossed to a fluorescent cDC1 reporter (KP-XCR1venus) to allow the detection of cDC1-CD8T cell clusters in tumor tissues across tumor stages. We found that cDC1-CD8 clusters are abundant and productive at the early stages of tumor development but progressively diminish in advanced tumors. Transcriptional profiling and flow cytometry identified the adhesion molecule ALCAM/CD166 (Activated Leukocyte Cell Adhesion Molecule, ligand of CD6) as highly expressed by lung cDC1 and significantly downregulated in advanced tumors. Analysis of human datasets indicated that ALCAM is downregulated in non-small cell lung cancer and its expression correlates to better prognosis. Mechanistically, triggering ALCAM on lung cDC1 induces cytoskeletal remodeling and contact formation whereas its blockade prevents T-cell activation. Together, our results indicate that ALCAM is important to stabilize cDC1-CD8 interactions at early tumor stages, while its loss in advanced tumors contributes to immune evasion.

Tim4 enables large peritoneal macrophages to cross-present tumor antigens at early stages of tumorigenesis.

Receptors controlling the cross-presentation of tumor antigens by macrophage subsets in cancer tissues are poorly explored. Here, we show that TIM4+ large peritoneal macrophages efficiently capture and cross-present tumor-associated antigens at early stages of peritoneal infiltration by ovarian cancer cells. The phosphatidylserine (PS) receptor TIM4 promotes maximal uptake of dead cells or PS-coated artificial targets and triggers inflammatory and metabolic gene programs in combination with cytoskeletal remodeling and upregulation of transcriptional signatures related to antigen processing. At the cellular level, TIM4-mediated engulfment induces nucleation of F-actin around nascent phagosomes, delaying the recruitment of vacuolar ATPase, acidification, and cargo degradation. In vivo, TIM4 deletion blunts induction of early anti-tumoral effector CD8 T cells and accelerates the progression of ovarian tumors. We conclude that TIM4-mediated uptake drives the formation of specialized phagosomes that prolong the integrity of ingested antigens and facilitate cross-presentation, contributing to immune surveillance of the peritoneum.

Dendritic cell-targeted therapy expands CD8 T cell responses to bona-fide neoantigens in lung tumors.

Cross-presentation by type 1 DCs (cDC1) is critical to induce and sustain antitumoral CD8 T cell responses to model antigens, in various tumor settings. However, the impact of cross-presenting cDC1 and the potential of DC-based therapies in tumors carrying varied levels of bona-fide neoantigens (neoAgs) remain unclear. Here we develop a hypermutated model of non-small cell lung cancer in female mice, encoding genuine MHC-I neoepitopes to study neoAgs-specific CD8 T cell responses in spontaneous settings and upon Flt3L + αCD40 (DC-therapy). We find that cDC1 are required to generate broad CD8 responses against a range of diverse neoAgs. DC-therapy promotes immunogenicity of weaker neoAgs and strongly inhibits the growth of high tumor-mutational burden (TMB) tumors. In contrast, low TMB tumors respond poorly to DC-therapy, generating mild CD8 T cell responses that are not sufficient to block progression. scRNA transcriptional analysis, immune profiling and functional assays unveil the changes induced by DC-therapy in lung tissues, which comprise accumulation of cDC1 with increased immunostimulatory properties and less exhausted effector CD8 T cells. We conclude that boosting cDC1 activity is critical to broaden the diversity of anti-tumoral CD8 T cell responses and to leverage neoAgs content for therapeutic advantage.

EMID2 is a novel biotherapeutic for aggressive cancers identified by in vivo screening.

BACKGROUND: New drugs to tackle the next pathway or mutation fueling cancer are constantly proposed, but 97% of them are doomed to fail in clinical trials, largely because they are identified by cellular or in silico screens that cannot predict their in vivo effect. METHODS: We screened an Adeno-Associated Vector secretome library (> 1000 clones) directly in vivo in a mouse model of cancer and validated the therapeutic effect of the first hit, EMID2, in both orthotopic and genetic models of lung and pancreatic cancer. RESULTS: EMID2 overexpression inhibited both tumor growth and metastatic dissemination, consistent with prolonged survival of patients with high levels of EMID2 expression in the most aggressive human cancers. Mechanistically, EMID2 inhibited TGFß maturation and activation of cancer-associated fibroblasts, resulting in more elastic ECM and reduced levels of YAP in the nuclei of cancer cells. CONCLUSION: This is the first in vivo screening, precisely designed to identify proteins able to interfere with cancer cell invasiveness. EMID2 was selected as the most potent protein, in line with the emerging relevance of the tumor extracellular matrix in controlling cancer cell invasiveness and dissemination, which kills most of cancer patients.

A mitochondrial quality control mechanism reverses the phagosome maturation arrest caused by Mycobacterium tuberculosis.

Phagosome maturation arrest (PMA) imposed by Mycobacterium tuberculosis ( Mtb ) is a classic tool that helps Mtb evade macrophage anti-bacterial responses. The exclusion of RAB7, a small GTPase, from Mtb -phagosomes underscores PMA. Here we report an unexpected mechanism that triggers crosstalk between the mitochondrial quality control (MQC) and the phagosome maturation pathways that reverses the PMA. CRISPR-mediated p62/SQSTM1 depletion ( p62 KD ) blocks mitophagy flux without impacting mitochondrial quality. In p62 KD cells, Mtb growth and survival are diminished, mainly through witnessing an increasingly oxidative environment and increased lysosomal targeting. The lysosomal targeting of Mtb is facilitated by enhanced TOM20 + mitochondria-derived vesicles (MDVs) biogenesis, a key MQC mechanism. In p62 KD cells, TOM20 + -MDVs biogenesis is MIRO1/MIRO2-dependent and delivered to lysosomes for degradation in a RAB7-dependent manner. Upon infection in p62 KD cells, TOM20 + -MDVs get extensively targeted to Mtb -phagosomes, inadvertently facilitating RAB7 recruitment, PMA reversal and lysosomal targeting of Mtb . Triggering MQC collapse in p62 KD cells further diminishes Mtb survival signifying cooperation between redox- and lysosome-mediated mechanisms. The MQC-anti-bacterial pathway crosstalk could be exploited for host-directed anti-tuberculosis therapies.

CXCL5-mediated accumulation of mature neutrophils in lung cancer tissues impairs the differentiation program of anticancer CD8 T cells and limits the efficacy of checkpoint inhibitors.

Lung tumor-infiltrating neutrophils are known to support growth and dissemination of cancer cells and to suppress T cell responses. However, the precise impact of tissue neutrophils on programming and differentiation of anticancer CD8 T cells in vivo remains poorly understood. Here, we identified cancer cell-autonomous secretion of CXCL5 as sufficient to drive infiltration of mature, protumorigenic neutrophils in a mouse model of non-small cell lung cancer (NSCLC). Consistently, CXCL5 transcripts correlate with neutrophil density and poor prognosis in a large human lung adenocarcinoma compendium. CXCL5 genetic deletion, unlike antibody-mediated depletion, completely and selectively prevented neutrophils accumulation in lung tissues. Depletion of tumor-infiltrating neutrophils promoted expansion of tumor-specific CD8 T cells, differentiation into effector cells and acquisition of cytolytic functions. Transfer of effector CD8 T cells into neutrophil-rich tumors, inhibited IFN-ϒ production, indicating active suppression of effector functions. Importantly, blocking neutrophils infiltration in the lung, overcame resistance to checkpoint blockade. Hence, this study demonstrates that neutrophils curb acquisition of cytolytic functions in lung tumor tissues and suggests targeting of CXCL5 as a strategy to restore anti-tumoral T cell functions.

Self-DNA Sensing by cGAS-STING and TLR9 in Autoimmunity: Is the Cytoskeleton in Control?

Modified or misplaced DNA can be recognized as a danger signal by mammalian cells. Activation of cellular responses to DNA has evolved as a defense mechanism to microbial infections, cellular stress, and tissue damage, yet failure to control this mechanism can lead to autoimmune diseases. Several monogenic and multifactorial autoimmune diseases have been associated with type-I interferons and interferon-stimulated genes (ISGs) induced by deregulated recognition of self-DNA. Hence, understanding how cellular mechanism controls the pathogenic responses to self-nucleic acid has important clinical implications. Fine-tuned membrane trafficking and cellular compartmentalization are two major factors that balance activation of DNA sensors and availability of self-DNA ligands. Intracellular transport and organelle architecture are in turn regulated by cytoskeletal dynamics, yet the precise impact of actin remodeling on DNA sensing remains elusive. This review proposes a critical analysis of the established and hypothetical connections between self-DNA recognition and actin dynamics. As a paradigm of this concept, we discuss recent evidence of deregulated self-DNA sensing in the prototypical actin-related primary immune deficiency (Wiskott-Aldrich syndrome). We anticipate a broader impact of actin-dependent processes on tolerance to self-DNA in autoimmune disorders.

Priming of the cGAS-STING-TBK1 Pathway Enhances LPS-Induced Release of Type I Interferons.

Cytoplasmic nucleic acids sensing through cGAS-STING-TBK1 pathway is crucial for the production of antiviral interferons (IFNs). IFN production can also be induced by lipopolysaccharide (LPS) stimulation through Toll-like receptor 4 (TLR4) in appropriate conditions. Of note, both IFN production and dysregulated LPS-response could play a role in the pathogenesis of Systemic Lupus Erythematosus (SLE). Indeed, LPS can trigger SLE in lupus-prone mice and bacterial infections can induce disease flares in human SLE. However, the interactions between cGAS and TLR4 pathways to IFNs have been poorly investigated. To address this issue, we studied LPS-stimulation in cellular models with a primed cGAS-STING-TBK1 pathway. cGAS-stimulation was naturally sustained by undigested self-nucleic acids in fibroblasts from DNase2-deficiency interferonopathy, whilst it was pharmacologically obtained by cGAMP-stimulation in THP1 cells and murine bone marrow-derived dendritic cells. We showed that cells with a primed cGAS-STING-TBK1 pathway displayed enhanced IFNs production after TLR4-challenge. STING-inhibition did not affect IFN production after LPS alone, but prevented the amplified IFN production in cGAMP-primed cells, suggesting that functional STING is required for priming-dependent enhancement. Furthermore, we speculated that an increased PIK3AP1 expression in DNase2-deficient fibroblasts may link cGAMP-priming with increased LPS-induced IFN production. We showed that both the hyper-expression of PIK3API and the enhanced LPS-induced IFN production can be contrasted by STING inhibitors. Our results may explain how bacterial LPS can synergize with cGAS-pathway in promoting the development of SLE-like autoimmunity.

Genetic lineage tracing reveals poor angiogenic potential of cardiac endothelial cells.

AIMS: Cardiac ischaemia does not elicit an efficient angiogenic response. Indeed, lack of surgical revascularization upon myocardial infarction results in cardiomyocyte death, scarring, and loss of contractile function. Clinical trials aimed at inducing therapeutic revascularization through the delivery of pro-angiogenic molecules after cardiac ischaemia have invariably failed, suggesting that endothelial cells in the heart cannot mount an efficient angiogenic response. To understand why the heart is a poorly angiogenic environment, here we compare the angiogenic response of the cardiac and skeletal muscle using a lineage tracing approach to genetically label sprouting endothelial cells. METHODS AND RESULTS: We observed that overexpression of the vascular endothelial growth factor in the skeletal muscle potently stimulated angiogenesis, resulting in the formation of a massive number of new capillaries and arterioles. In contrast, response to the same dose of the same factor in the heart was blunted and consisted in a modest increase in the number of new arterioles. By using Apelin-CreER mice to genetically label sprouting endothelial cells we observed that different pro-angiogenic stimuli activated Apelin expression in both muscle types to a similar extent, however, only in the skeletal muscle, these cells were able to sprout, form elongated vascular tubes activating Notch signalling, and became incorporated into arteries. In the heart, Apelin-positive cells transiently persisted and failed to give rise to new vessels. When we implanted cancer cells in different organs, the abortive angiogenic response in the heart resulted in a reduced expansion of the tumour mass. CONCLUSION: Our genetic lineage tracing indicates that cardiac endothelial cells activate Apelin expression in response to pro-angiogenic stimuli but, different from those of the skeletal muscle, fail to proliferate and form mature and structured vessels. The poor angiogenic potential of the heart is associated with reduced tumour angiogenesis and growth of cancer cells.

TIM4 expression by dendritic cells mediates uptake of tumor-associated antigens and anti-tumor responses.

Acquisition of cell-associated tumor antigens by type 1 dendritic cells (cDC1) is essential to induce and sustain tumor specific CD8+ T cells via cross-presentation. Here we show that capture and engulfment of cell associated antigens by tissue resident lung cDC1 is inhibited during progression of mouse lung tumors. Mechanistically, loss of phagocytosis is linked to tumor-mediated downregulation of the phosphatidylserine receptor TIM4, that is highly expressed in normal lung resident cDC1. TIM4 receptor blockade and conditional cDC1 deletion impair activation of tumor specific CD8+ T cells and promote tumor progression. In human lung adenocarcinomas, TIM4 transcripts increase the prognostic value of a cDC1 signature and predict responses to PD-1 treatment. Thus, TIM4 on lung resident cDC1 contributes to immune surveillance and its expression is suppressed in advanced tumors.

Wiskott-Aldrich syndrome protein restricts cGAS/STING activation by dsDNA immune complexes.

Dysregulated sensing of self-nucleic acid is a leading cause of autoimmunity in multifactorial and monogenic diseases. Mutations in Wiskott-Aldrich syndrome protein (WASp), a key regulator of cytoskeletal dynamics in immune cells, cause autoimmune manifestations and increased production of type I IFNs by innate cells. Here we show that immune complexes of self-DNA and autoantibodies (DNA-ICs) contribute to elevated IFN levels via activation of the cGAS/STING pathway of cytosolic sensing. Mechanistically, lack of endosomal F-actin nucleation by WASp caused a delay in endolysosomal maturation and prolonged the transit time of ingested DNA-ICs. Stalling in maturation-defective organelles facilitated leakage of DNA-ICs into the cytosol, promoting activation of the TBK1/STING pathway. Genetic deletion of STING and STING and cGAS chemical inhibitors abolished IFN production and rescued systemic activation of IFN-stimulated genes in vivo. These data unveil the contribution of cytosolic self-nucleic acid sensing in WAS and underscore the importance of WASp-mediated endosomal actin remodeling in preventing innate activation.

HLA-A, -B, -C expression in colon carcinoma mimics that of the normal colonic mucosa and is prognostically relevant.

Whether human leukocyte antigen (HLA)-A, -B, -C expression has any predictive value on the prognosis of human malignancies remains controversial. Herein, monoclonal antibodies with preferential reactivity for HLA-A, HLA-B, and HLA-C (HCA2, HC10, and L31) were used to stain an archival collection of 291 formalin-fixed/paraffin-embedded tissues, comprising neoplastic lesions from stages II and III colon carcinoma patients (n=165), and the uninvolved, morphologically normal mucosae from a subset (n=126) of these patients. Marked staining variability was detected not only in the tumors as in previous studies, but also in the normal paired mucosae. HLA-A, -B, -C expression was similar in approximately two thirds of the available 126 normal/neoplastic pairs, confirming in vivo our previous observation that most tumor cells mimic the HLA phenotypes of their normal counterparts. Both up and down-regulation occurred in the remaining third of the pairs, but did not coincide with high and low expression, respectively, conventionally evaluated on the tumor lesion only. Remarkably, a "paired" evaluation, but not high or low expression in the tumor, was predictive of the clinical outcome. Deviations from the expression in the normal paired mucosa (both increases and decreases) of HCA2-reactive class I molecules (possibly HLA-A), and down-regulation of L31-reactive class I molecules (possibly HLA-C), particularly in tumors from stage II patients, correlated with poor 5-year overall and disease-free survival, hazard risk ranging from 2 to 6, approximately. Thus, a paired immunohistochemical comparison reveals a novel immune evasion strategy that may impact on the prognosis of colon carcinoma.

The SNARE VAMP7 Regulates Exocytic Trafficking of Interleukin-12 in Dendritic Cells.

Interleukin-12 (IL-12), produced by dendritic cells in response to activation, is central to pathogen eradication and tumor rejection. The trafficking pathways controlling spatial distribution and intracellular transport of IL-12 vesicles to the cell surface are still unknown. Here, we show that intracellular IL-12 localizes in late endocytic vesicles marked by the SNARE VAMP7. Dendritic cells (DCs) from VAMP7-deficient mice are partially impaired in the multidirectional release of IL-12. Upon encounter with antigen-specific T cells, IL-12-containing vesicles rapidly redistribute at the immune synapse and release IL-12 in a process entirely dependent on VAMP7 expression. Consistently, acquisition of effector functions is reduced in T cells stimulated by VAMP7-null DCs. These results provide insights into IL-12 intracellular trafficking pathways and show that VAMP7-mediated release of IL-12 at the immune synapse is a mechanism to transmit innate signals to T cells.

[Anatomico-surgical contribution to the knowledge of the lymphatic spread of gastric adenocarcinoma]. / Contributo anatomochirurgico alla conoscenza della diffusione linfatica dell'adenocarcinoma gastrico.

Following the researches performed on lymphatic spread of gastric carcinoma, our study aimed to add useful informations to establish the extension of exeresis with radical intent on the basis of recent studies on sentinel node mapping. The study includes 120 consecutive cases of gastric cancer operated between 1996 and 2000. Sixty-nine (57.5%) males and 51 (42.5%) females, with age ranging between 29 and 84 years, were evaluated. Cancer location was in 17 patients upper third, in 35 middle third, in 59 distal third and in 9 cases gastric stump. Early cases (T1-2) were 65 and advanced cases (T3-4) were 55. Sixty-eight STG and 52 TG were performed with 21 D1, 73 D2 and 26 D3 lymphoadenectomy. Overall 3501 lymph-nodes were examined. Eighty-two cases (68%) showed lymph-nodal metastases, while 38 (32%) were negative. The lymphatic spread of gastric cancer resulted related to the depth of wall invasion (T): 25% of T1, 75% of T2, 85% of T3 and 95% of T4 were node positive (N+). The correlation between T and N+ was also significative concerning the diffusion to the first, second and third level stations, increasing with the depth of wall invasion. The possibility of extension to one single lymphnodal station was inversely related to the T. When the first level stations were negative the second and third were never positive. This study seems to confirm the complex but systematic and predictable lymphatic gastric flow. The skip metastases, rare but described in other retrospective studies, were never observed. Our study shows that sentinel node mapping could be reliable also for gastric cancer surgery, allowing tailored and less aggressive resections. Meanwhile, from this analysis it appears that nodal stations 7-8 should be included in the first level lymphoadenectomy, widening D1 exeresis considered until now sufficient in less advanced cases. In conclusion, studies of lymphatic spread and sentinel node mapping seems to require a different therapeutic approach to gastric cancer concerning D1 lymphoadenectomy, tailoring the exeresis on the basis of sentinel node mapping in negative T1-2 cases, but systematically widening the lymphoadenectomy from the perigastric only, to 7 and 8 stations.

A pathobiologic link between risk factors profile and morphological markers of carotid instability.

OBJECTIVE: Although cardiovascular risk factors have been strongly linked to carotid intimal-media thickness, their association with plaque progression towards instability is poorly understood. We evaluated a large database of endarterectomy specimens removed from symptomatic and asymptomatic patients to determine the correlation between major cardiovascular risk factors and carotid plaque morphology. METHODS: Incidence of thrombotic, vulnerable and stable plaques together with the degree of plaque inflammatory infiltration was evaluated in 457 carotid atherosclerotic lesions. Clinical records were reviewed in all cases for risk factors profile. RESULTS: Thrombotic plaques were more frequently observed in patients affected by stroke (66.9%) as compared to TIA (36.1%) and asymptomatic patients (26.8%, p<0.001). Out of 457 carotid plaques removed during carotid endarterectomy, 181 (39.6%) were represented by thrombotic plaques, 72 (15.8%) by vulnerable plaques (thin cap fibroateroma) and 204 (44.6%) by stable plaques. At the multivariate analysis, a strong association was observed between hypertension, low HDL-cholesterol (HDL-C) and ratio of total to HDL-C >5 with vulnerable and thrombotic carotid plaques. Hypertension (p=0.001), hypercholesterolemia (p=0.05) and low HDL-C (p=0.001) significantly also correlated with the presence of high inflammatory infiltrate of the plaque. When multivariate analysis was restricted to asymptomatic patients, hypertension (p=0.009, OR 2.29), low HDL-cholesterol (p=0.01 OR 2.21) and the ratio of total to HDL-C >5 (p=0.03, OR 2.07) were confirmed to be the risk factors most significantly associated to unstable plaques. The relative risk to carry an unstable plaque for asymptomatic patients with high Framingham Risk Score as compared with those with low risk score was 2.06 (95% C.I., 1.26-3.36). CONCLUSIONS: The present histopathological study identifies risk factors predictive of increased risk of carotid plaque rupture and thrombosis. Asymptomatic patients with high risk factors profile may constitute a specific target to reduce the likelihood of cerebrovascular accidents even in the presence of non-flow-limiting plaque.

Immunohistochemical expression of p16(INK4a) is predictive of HR-HPV infection in cervical low-grade lesions.

The p16(INK4a) is a cyclin-dependent kinase inhibitor that decelerates the cell cycle by inactivating the cyclin-dependent kinases involved in the phosphorylation of the retinoblastoma protein (RB). Expression of E6 and E7 oncogenes of high-risk (HR) human papillomavirus (HPV), affecting the RB-p16 pathway, leads to p16 upregulation. Although it is widely reported that p16 is overexpressed in a high percentage of preneoplastic lesions and in almost all carcinomas of the uterine cervix, protein upregulation and its correlation with HPV infection in low-grade lesions is still being debated. In this study, we investigated in parallel, p16 expression and HPV infection in 100 cervical biopsies (17 normal tissues, 54 CIN1, 10 CIN2, 11 CIN3, eight invasive squamous cancers). Results obtained demonstrated that none of the 17 normal cervical tissues, evaluated by immunohistochemistry, presented p16 positivity whereas, starting from CIN1 (31%) to CIN2 (90%), CIN3 (100%) and carcinomas (100%), a constant and significant increase of protein overexpression (P<0.0001) was observed. In addition, p16 overexpression consistently showed elevated sensitivity (84%) and specificity (98%) in detecting HR-HPV infection with a high positive predictive value (97%) and negative predictive value (86%). Of interest, 93% of the p16-positive CIN1 were also HR-HPV infected. Our findings confirmed that p16 overexpression is associated to high-grade precancerous lesions and cervical carcinomas, and further demonstrated that immunohistochemical evaluation of p16 may be a useful biomarker in identifying HR-HPV-infected low-grade lesions.

Chromogenic in situ hybridization to detect HER-2/neu gene amplification in histological and ThinPrep-processed breast cancer fine-needle aspirates: a sensitive and practical method in the trastuzumab era.

The increasing evidence of trastuzumab efficacy in breast cancer (BC) patients means that an accurate and reproducible evaluation of HER-2 statusis of paramount importance in histological and in cytological samples. Currently, the two main methods used to analyze HER-2 amplification or overexpression are fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC). Although the two methods are strongly correlated for histological tissue, the evaluation of tumor morphology through FISH may be difficult and fluorescence fades quickly. These limitations can be overcome by chromogenic in situ hybridization (CISH), which can visualize the amplification product along with morphological features. In view of this, in the present study, we analyzed the usefulness of CISH on formalin-fixed, paraffin-embedded (FFPE) BC specimens and investigated whether CISH can be a valid technique in the determination of HER-2 status for fine-needle aspirates (FNAs) processed by liquid-based cytology. The results we obtained in a retrospective series of 111 FFPE BC specimens demonstrated good concordance between CISH and IHC and between CISH and FISH. The former concordance was comparable with that observed between FISH and IHC. When CISH was applied to a prospective series of 53 FNAs, from surgically removed BC, our data showed evidence of a higher concordance of results between liquid-based cytology and the companion FFPE tissues using CISH rather than HercepTesttrade mark. Therefore, CISH analysis, which is avaluable and reproducible alternative to FISH for selecting breast cancer patients for trastuzumab therapy, can lower false-positive immunocytochemistry findings in ThinPrep-processed FNAs.