VEGF expression in colorectal cancer metastatic lymph nodes: clinicopathological correlation and prognostic significance

Background: Angiogenesis plays an important role in colorectal cancer (CRC) tumorigenesis and metastatic progression. Methods: The present series consisted of CRC lymph node metastasis (LNM) tissue samples from 210 patients. Archival paraffin embedded LNM tissue were used to build up tissue microarray blocks and VEGF expression was immunohistochemically assessed. Results: VEGF-A and VEGF-C are overexpressed in LNM. VEGF-A was associated with patient age (p p = 0.032; p = 0.030, respectively). VEGF-C positivity was associated with VEGFR-3 positivity (p = 0.031), and VEGF-D with VEGFR-2 and VEGFR-3 (p ≤ 0.001). Matching the expression in LNM with CRC, in CRC VEGF-A positivity associates with VEGF-A, VEGF-C, VEGF-D, VEGF-R2, VEGF-R3 positivity in LNM; CRC VEGF-C with VEGF-D, VEGFR-2, VEGFR-3; CRC VEGFR-2 with VEGF-A, VEGF-C, VEGF-D, VEGFR-2, VEGFR-3; CRC VEGFR-3 with VEGF-A, VEGF-C, VEGF-D, VEGFR-2, VEGFR-3 in LNM. Conclusion: This study provides new information, revealing that VEGF family expression is increased in LNM. The association between the expression of VEGFR-2 and VEGFR-3 in LNM with CRC relapse reveals its impact on patient prognosis. Interesting data were found when the relationship between these proteins in primary tumor and their metastasis, were analyzed; VEGFA positivity in primary tumor is positively related to VEGF-A, VEGF-C, VEGF-D, VEGFR-2 and VEGFR-3 in their respective LNM suggesting mutual influence.This research received no external funding

Role of Keratinocytes in Sensitive Skin

Sensitive skin is a clinical syndrome defined by the occurrence of unpleasant sensations such as burning, stinging, tingling, pricking, or itching in response to various normally innocuous physical, chemical, and thermal stimuli. These particular symptoms have led the consideration of a potential dysfunction of the intra-epidermal nerve fibers (IENF) that are responsible for pain, temperature, and itch perception. This neuronal hypothesis has just been reinforced by recent studies suggesting that sensitive skin could become assimilated to small fiber neuropathy. Meanwhile, the involvement of keratinocytes, the pre-dominant epidermal cell type, has so far mainly been considered because of their role in the epidermal barrier. However, keratinocytes also express diverse sensory receptors present on sensory neurons, such as receptors of the transient receptor potential (TRP) family, including Transient Receptor Potential Vallinoid 1 (TRPV1), one of the main transducers of painful heat which is also involved in itch transduction, and Transient Receptor Potential Vallinoid 4 (TRPV4) which is depicted as a heat sensor. While TRPV1 and TRPV4 are expressed both by sensory neurons and keratinocytes, it has recently been demonstrated that the specific and selective activation of TRPV1 on keratinocytes is sufficient to induce pain. Similarly, the targeted activation of keratinocyte-expressed TRPV4 elicits itch and the resulting scratching behavior. So, contrary to classical conception, the IENF are not the exclusive transducers of pain and itch. In light of these recent advances, this review proposes to consider the putative role of epidermal keratinocytes in the generation of the unpleasant sensations characteristic of sensitive skin syndrome

NRAS Q61R , BRAF V600E immunohistochemistry: a concomitant tool for mutation screening in melanomas

International audienceThe determination of NRAS and BRAF mutation status is a major requirement in the treatment of patients with metastatic melanoma. Mutation specific antibodies against NRAS(Q61R) and BRAF(V600E) proteins could offer additional data on tumor heterogeneity. The specificity and sensitivity of NRAS(Q61R) immunohistochemistry have recently been reported excellent. We aimed to determine the utility of immunohistochemistry using SP174 anti-NRAS(Q61R) and VE1 anti-BRAF(V600E) antibodies in the theranostic mutation screening of melanomas. 142 formalin-fixed paraffin-embedded melanoma samples from 79 patients were analyzed using pyrosequencing and immunohistochemistry. 23 and 26 patients were concluded to have a NRAS-mutated or a BRAF-mutated melanoma respectively. The 23 NRAS (Q61R) and 23 BRAF (V600E) -mutant samples with pyrosequencing were all positive in immunohistochemistry with SP174 antibody and VE1 antibody respectively, without any false negative. Proportions and intensities of staining were varied. Other NRAS (Q61L) , NRAS (Q61K) , BRAF (V600K) and BRAF (V600R) mutants were negative in immunohistochemistry. 6 single cases were immunostained but identified as wild-type using pyrosequencing (1 with SP174 and 5 with VE1). 4/38 patients with multiple samples presented molecular discordant data. Technical limitations are discussed to explain those discrepancies. Anyway we could not rule out real tumor heterogeneity. In our study, we showed that combining immunohistochemistry analysis targeting NRAS(Q61R) and BRAF(V600E) proteins with molecular analysis was a reliable theranostic tool to face challenging samples of melanoma

Cytological diagnostic features of late breast implant seromas. From reactive to anaplastic large cell lymphoma

Late breast implant seroma may be the presentation of a breast implant-associated anaplastic large cell lymphoma (BI-ALCL), which claims for a prompt recognition. However, BI-ALCL diagnosis on fine-needle aspiration (FNA) might be challenging for pathologists lacking experience with peri-implant breast effusions. Sixty-seven late breast implant seromas collected by FNA from 50 patients were evaluated by Papanicolaou smear stain and immunocytochemistry on cell blocks. A diagnostic algorithm based on the cellular composition, cell morphology and percentage of CD30+ cells was developed. Histological evaluation of the corresponding peri-prosthetic capsules was also performed. Most of the effusions (91% of the samples) were classified as reactive and 9% as BI-ALCL. In the BI-ALCL cases, medium-to-large atypical cells expressing CD30 represented more than 70% of the cellularity, whereas in in the reactive effusions CD30+ elements were extremely rare (<5%) and consisted of non-atypical elements. The reactive effusions were categorized into three patterns: i) acute infiltrate with prominent neutrophilic component (33% of the samples); ii) mixed infiltrate characterized by a variable number of neutrophils, lymphocytes and macrophages (30% of the samples); iii) chronic infiltrate composed predominantly of T lymphocytes or macrophages with only sporadic granulocytes (37% of the samples). The inflammatory cytological patterns were consistent with the histology of the corresponding capsules. Our results indicate that cytological analysis of late breast implant effusions, supported by the knowledge of the heterogeneous cytomorphological spectrum of late seromas, is a valuable approach for the early recognition of BI-ALCL

Determination of chemical irritation potential using a defined gene signature set on tissue-engineered human skin equivalents

There are no physical or visual manifestations that define skin sensitivity or irritation; a subjective diagnosis is made based on the evaluation of clinical presentations including burning, prickling, erythema and itching. Adverse skin reaction in response to topically applied products is common and can limit the use of dermatological or cosmetic products. The purpose of this study was to evaluate the use of human skin equivalents (HSE) based on immortalised skin keratinocytes and evaluate the potential of a 22-gene panel in combination with multivariate analysis to discriminate between chemicals known to act as irritants and those that do not. Test compounds were applied topically to full thickness HSE or human ex vivo skin and gene signatures determined for known irritants and non-irritants. Principle component analysis showed the discriminatory potential of the 22-gene panel. Linear discrimination analysis, performed to further refine the gene set for a more high-throughput analysis, identified a putative seven-gene panel (IL-6, PTGS2, ATF3, TRPV3, MAP3K8, HMGB2 and MMP-3) that could distinguish potential irritants from non-irritants. These data offer promise as an in vitro prediction tool, although analysis of a large chemical test set is required to further evaluate the system

Caractérisation des zones de contact entre kératinocytes et neurones sensoriels

The skin is a sensory organ containing a wide variety of sensory end organs. Among them, intraepidermal free nerve endings, described in the intercellular spaces of the epidermis, especially keratinocytes, are considered as conveying information about temperature, pain and itch (article 1). Using confocal laser-scanning microscopy in human skin biopsies, we demonstrate that nerve fibres also progress in keratinocyte cytoplasmic tunnels. Contacts between keratinocytes and sensory neurons are also much more intimate than expected (article 2). It has only recently been demonstrated that keratinocytes can transduce nociceptive information. To understand the mechanisms underlying keratinocyte communication with sensory neurons, we performed co-cultures of keratinocytes and sensory neurons. Using multi-modal imaging, molecular and functional approaches, we reveal the existence of en passant chemical synapses between epidermal keratinocytes and intra-epidermal nerve endings (article 3). This discovery of synaptic structures is a paradigm shift that leads to consider the whole epidermis as a sensory epithelium. Finally, a review including our results shows how the physical contacts between sensory neurons and epidermal cells contribute to the dialogue between the skin, the nervous system and the immune system, anatomically defining the neuro-immuno-cutaneous system (article 4).La peau est un organe sensoriel, par définition richement innervé. Parmi les divers récepteurs cutanés, les fibres nerveuses libres intra-épidermiques sont considérées comme percevant directement les informations douloureuses et thermiques ou encore le prurit (article 1). Elles sont classiquement décrites comme cheminant entre les cellules épidermiques, en particulier les kératinocytes. L’étude de biopsies cutanées en microscopie confocale nous permet dans un premier temps de démontrer que ces fibres progressent également dans des tunnels kératinocytaires, révélant ainsi que les rapports entre kératinocytes et fibres nerveuses sont plus intimes que précédemment décrits (article 2). Alors qu’il a été récemment démontré que les kératinocytes peuvent également percevoir des informations nociceptives et activer ces fibres nerveuses, nous avons par ailleurs développé un modèle de co-culture de kératinocytes et de neurones sensoriels afin de caractériser les modalités de communication entre ces cellules. En nous appuyant sur une triple approche morphologique, moléculaire et fonctionnelle, nous révélons l’existence de synapses en passant entre les kératinocytes et les neurones sensoriels (article 3). La découverte de ces structures synaptiques constitue un changement de paradigme qui invite à considérer l’épiderme dans son ensemble comme un épithélium sensoriel. Dans un troisième temps, une revue de la littérature, incluant nos résultats, explore la façon dont les contacts entre les neurones sensoriels et les différentes cellules épidermiques contribuent au dialogue entre la peau, le système nerveux et le système immunitaire, définissant anatomiquement le système neuro-immuno-cutané (article 4)

Characterization of contact areas between keratinocytes and sensory neurons

La peau est un organe sensoriel, par définition richement innervé. Parmi les divers récepteurs cutanés, les fibres nerveuses libres intra-épidermiques sont considérées comme percevant directement les informations douloureuses et thermiques ou encore le prurit (article 1). Elles sont classiquement décrites comme cheminant entre les cellules épidermiques, en particulier les kératinocytes. L’étude de biopsies cutanées en microscopie confocale nous permet dans un premier temps de démontrer que ces fibres progressent également dans des tunnels kératinocytaires, révélant ainsi que les rapports entre kératinocytes et fibres nerveuses sont plus intimes que précédemment décrits (article 2). Alors qu’il a été récemment démontré que les kératinocytes peuvent également percevoir des informations nociceptives et activer ces fibres nerveuses, nous avons par ailleurs développé un modèle de co-culture de kératinocytes et de neurones sensoriels afin de caractériser les modalités de communication entre ces cellules. En nous appuyant sur une triple approche morphologique, moléculaire et fonctionnelle, nous révélons l’existence de synapses en passant entre les kératinocytes et les neurones sensoriels (article 3). La découverte de ces structures synaptiques constitue un changement de paradigme qui invite à considérer l’épiderme dans son ensemble comme un épithélium sensoriel. Dans un troisième temps, une revue de la littérature, incluant nos résultats, explore la façon dont les contacts entre les neurones sensoriels et les différentes cellules épidermiques contribuent au dialogue entre la peau, le système nerveux et le système immunitaire, définissant anatomiquement le système neuro-immuno-cutané (article 4).The skin is a sensory organ containing a wide variety of sensory end organs. Among them, intraepidermal free nerve endings, described in the intercellular spaces of the epidermis, especially keratinocytes, are considered as conveying information about temperature, pain and itch (article 1). Using confocal laser-scanning microscopy in human skin biopsies, we demonstrate that nerve fibres also progress in keratinocyte cytoplasmic tunnels. Contacts between keratinocytes and sensory neurons are also much more intimate than expected (article 2). It has only recently been demonstrated that keratinocytes can transduce nociceptive information. To understand the mechanisms underlying keratinocyte communication with sensory neurons, we performed co-cultures of keratinocytes and sensory neurons. Using multi-modal imaging, molecular and functional approaches, we reveal the existence of en passant chemical synapses between epidermal keratinocytes and intra-epidermal nerve endings (article 3). This discovery of synaptic structures is a paradigm shift that leads to consider the whole epidermis as a sensory epithelium. Finally, a review including our results shows how the physical contacts between sensory neurons and epidermal cells contribute to the dialogue between the skin, the nervous system and the immune system, anatomically defining the neuro-immuno-cutaneous system (article 4)

Caractérisation des zones de contact entre kératinocytes et neurones sensoriels

The skin is a sensory organ containing a wide variety of sensory end organs. Among them, intraepidermal free nerve endings, described in the intercellular spaces of the epidermis, especially keratinocytes, are considered as conveying information about temperature, pain and itch (article 1). Using confocal laser-scanning microscopy in human skin biopsies, we demonstrate that nerve fibres also progress in keratinocyte cytoplasmic tunnels. Contacts between keratinocytes and sensory neurons are also much more intimate than expected (article 2). It has only recently been demonstrated that keratinocytes can transduce nociceptive information. To understand the mechanisms underlying keratinocyte communication with sensory neurons, we performed co-cultures of keratinocytes and sensory neurons. Using multi-modal imaging, molecular and functional approaches, we reveal the existence of en passant chemical synapses between epidermal keratinocytes and intra-epidermal nerve endings (article 3). This discovery of synaptic structures is a paradigm shift that leads to consider the whole epidermis as a sensory epithelium. Finally, a review including our results shows how the physical contacts between sensory neurons and epidermal cells contribute to the dialogue between the skin, the nervous system and the immune system, anatomically defining the neuro-immuno-cutaneous system (article 4).La peau est un organe sensoriel, par définition richement innervé. Parmi les divers récepteurs cutanés, les fibres nerveuses libres intra-épidermiques sont considérées comme percevant directement les informations douloureuses et thermiques ou encore le prurit (article 1). Elles sont classiquement décrites comme cheminant entre les cellules épidermiques, en particulier les kératinocytes. L’étude de biopsies cutanées en microscopie confocale nous permet dans un premier temps de démontrer que ces fibres progressent également dans des tunnels kératinocytaires, révélant ainsi que les rapports entre kératinocytes et fibres nerveuses sont plus intimes que précédemment décrits (article 2). Alors qu’il a été récemment démontré que les kératinocytes peuvent également percevoir des informations nociceptives et activer ces fibres nerveuses, nous avons par ailleurs développé un modèle de co-culture de kératinocytes et de neurones sensoriels afin de caractériser les modalités de communication entre ces cellules. En nous appuyant sur une triple approche morphologique, moléculaire et fonctionnelle, nous révélons l’existence de synapses en passant entre les kératinocytes et les neurones sensoriels (article 3). La découverte de ces structures synaptiques constitue un changement de paradigme qui invite à considérer l’épiderme dans son ensemble comme un épithélium sensoriel. Dans un troisième temps, une revue de la littérature, incluant nos résultats, explore la façon dont les contacts entre les neurones sensoriels et les différentes cellules épidermiques contribuent au dialogue entre la peau, le système nerveux et le système immunitaire, définissant anatomiquement le système neuro-immuno-cutané (article 4)

Anatomical contacts between sensory neurons and epidermal cells: an unrecognized anatomical network for neuro-immuno-cutaneous crosstalk

Abstract Sensory neurons innervating the skin are conventionally thought to be the sole transducers of touch, temperature, pain and itch. However, recent studies have shown that keratinocytes – like Merkel cells – act as sensory transducers, whether for innocuous or noxious mechanical, thermal or chemical stimuli, and communicate with intraepidermal free nerve endings via chemical synaptic contacts. This paradigm shift leads to consideration of the whole epidermis as a sensory epithelium. Sensory neurons additionally function as an efferent system. Through the release of neuropeptides in intimate neuroepidermal contact areas, they contribute to epidermal homeostasis and to the pathogenesis of inflammatory skin diseases. To counteract the dogma regarding neurocutaneous interactions, seen exclusively from the perspective of soluble and spreading mediators, this review highlights the essential contribution of the unrecognized anatomical contacts between sensory neurons and epidermal cells (keratinocytes, melanocytes, Langerhans cells and Merkel cells), which take part in the reciprocal dialogue between the skin, nervous system and immune system