Inmunohistoquímica en dermatopatología: revisión de los anticuerpos utilizados con mayor frecuencia (parte i)

Papillomavirus-like particles as vectors for ex vivo gene therapy of the skin

Ex vivo gene delivery to the skin utilizing retroviral vectors has been demonstrated to be a viable clinical option for replacement of defective genes. However, because these vectors integrate their cargo into the genome, safety issues arise when utilizing them to deliver gene-editing nucleases. Here, we explored the use of Papillomavirus, a non-integrating viral vector, for ex vivo skin gene editing, exploiting its natural tropism for basal keratinocytes. We demonstrated that Papillomavirus-like particles (PVLPs) can deliver a variety of DNA constructs encoding fluorophores, Cre recombinase, calcium indicators, Cas9, and short hairpin RNA (shRNA) to keratinocytes, offering advantages over other viral vectors such as adeno-associated virus (AAV) and Lentivirus. We further showed that PVLPs can be used for gene therapy for Olmsted syndrome, a genetic skin disease caused by a gain-of-function mutation in the Trpv3 gene. Specifically, PVLP-delivered SaCas9 and shRNA effectively disrupted the Trpv3 gene or reduced its expression, leading to decreased TRPV3 activity and mitigating the hyperactivity associated with Olmsted syndrome. Skin equivalents generated from PVLP-treated keratinocytes exhibited complete transduction, and PVLP-shRNA treatment significantly reduced hyperkeratosis in skin equivalents from mice bearing the Olmsted syndrome mutation. These findings highlight PVLP as a promising tool for ex vivo skin gene therapy.

Microneedle-mediated treatment for superficial tumors by combining multiple strategies

Superficial tumors are still challenging to overcome due to the high risk and toxicity of surgery and conventional chemotherapy. Microneedles (MNs) are widely used in the treatment of superficial skin tumors (SST) due to the high penetration rate of the stratum corneum (SC), excellent biocompatibility, simple preparation process, high patient compliance, and minimal invasion. Most importantly, MNs can provide not only efficient and rarely painful delivery carriers, but also combine multi-model strategies with photothermal therapy (PTT), immunotherapy, and gene therapy for synergistic efficacy. To promote an in-depth understanding of their superiorities, this paper systematically summarized the latest application progress of MNs in the treatment of SST by delivering various types of photosensitizers, immune signal molecules, genes, and chemotherapy drugs. Just as important, the advantages, limitations, and drug release mechanisms of MNs based on different materials are introduced in the paper. In addition, the application of MN technology to clinical practice is the ultimate goal of all the work. The obstacles and possible difficulties in expanding the production of MNs and achieving clinical transformation are briefly discussed in this paper. To be anticipated, our work will provide new insights into the precise and rarely painful treatment of SST in the future.

A case of racemiform trichoblastoma in a dog

Trichoblastoma, which is common in dogs, is now occurring with other cellular changes outside the recognized forms to warrant their continuous evaluation for proper elucidation even as their causes largely remain unknown. A case at hand involved a 9-year-old Caucasian dog, which weighed 35 kg with chief complaint of a progressive bleeding mass on the scalp. The dog had an up-to-date vaccination record and all vital parameters were within optimum ranges. The surgical excision of the firm, solitary, and alopecic mass with traumatized upper surface revealed the presence of a well-demarcated and unencapsulated mass composed of grapes-like nests of basaloid epithelial cells within follicular stroma devoid of stromal necrosis, inflammatory cellular infiltration, and neoplastic epidermal connection. However, there was tissue necrosis, hemorrhages, and inflammatory cellular infiltrates on the exposed upper part of the traumatized growth. Immunohistochemical analysis showed positive reactivity to AE1/AE3, CK5/6, and p63 but negative immunoreactivity to CK7, CK20, CEA, and TTF-1. The histomorphological and immunohistochemical evaluation of the mass on the scalp of the dog suggested a solitary racemiform trichoblastoma with a traumatized exposed upper part despite basal cell carcinoma mimicry where histological diagnosis currently hold sway over immunohistochemical evaluation.

Microneedles-mediated drug delivery system for the diagnosis and treatment of melanoma

As an emerging novel drug delivery system, microneedles (MNs) have a wide range of applications in the medical field. They can overcome the physiological barriers of the skin, penetrate the outermost skin of the human body, and form hundreds of reversible microchannels to enhance the penetration of drugs and deliver drugs to the diseased sites. So they have great applications in the diagnosis and treatment of melanoma. Melanoma is a kind of malignant tumor, the survival rate of patients with metastases is extremely low. The traditional methods of surgery and drug treatment for melanoma are often accompanied by large adverse reactions in the whole body, and the drug concentration is low. The use of MNs for transdermal administration can increase the drug concentration, reduce adverse reactions in the treatment process, and have good therapeutic effect on melanoma. This paper introduced various types of MNs and their preparation methods, summarized the diagnosis and various treatment options for melanoma with MNs, focused on the treatment of melanoma with dissolved MNs, and made prospect of MNs-mediated transdermal drug delivery in the treatment of melanoma.

The complexity of cancer immunotherapy illustrated through skin tumors

BACKGROUND

Skin tumours are among the cancer types most sensitive to immunotherapy, due to their unique immunogenic features including skin-associated lymphoid tissue, high mutational load, overexpression of tumour antigens, and high frequency of viral antigens. Despite this high immunotherapy response rate, however, ultimately most skin tumours develop similar treatment resistance to most other malignant tumours, which highlights the need for in-depth study of mechanisms of response and resistance to immunotherapy.

METHODS

A bibliographic review of the most recent publications regarding currently in use and emerging biomarkers on skin tumors has been done.

RESULTS

Predictive biomarkers of treatment response, biomarkers that warn of possible resistance, and emerging markers, the majority of a systemic nature, are described. Including factors affecting not only genomics, but also the immune system, nervous system, microbiota, tumour microenvironment, metabolism and stress.

CONCLUSIONS

For accurate diagnosis of tumour type, knowledge of its functional mechanisms and selection of a comprehensive therapeutic protocol, this inclusive view of biology, health and disease is fundamental. This field of study could also become a valuable source of practical information applicable to other areas of oncology and immunotherapy.

Histological and Immunohistochemical Features of Trichoblastoma in a Sarda Breed Sheep

Simple Summary

Skin tumors in ruminants are occasionally reported and are mostly associated with the presence of oncogenic viruses, such as papillomavirus, or to direct skin exposure to solar radiation. Spontaneous tumors with adnexal differentiation, originating from the hair follicle or its associated glands, are even more rarely reported in these species. Investigation of the histological and immunohistochemical features of a trichoblastoma (tumor arising from the hair follicle) detected in the ear of a Sarda breed sheep, allowed for the study of comparative aspects of this tumor with other domestic species in which this neoplasm is commonly reported, such as in dogs and cats, and in human beings. This work contributed to the deepening of the knowledge of ovine spontaneous tumors unrelated to the presence of papillomaviruses.

Abstract

Skin tumors with adnexal differentiation are commonly reported in dogs and cats, while only anecdotal evidence is available in sheep. Here we illustrate the macroscopic, histologic, and immunohistochemical features of a cutaneous lesion with adnexal differentiation in a 6-year-old female Sarda breed sheep, surgically treated for a horn-like mass located in the left pinna. Additionally, we investigate a possible contribution of Ovine Papillomaviruses (OaPVs). Histologically, the dermis was expanded by an expansive and unencapsulated multilobulated nodule composed of cuboidal to spindle basaloid cells arranged in variably-sized cytokeratins (CK) AE1-AE3, CK 5/6 and CK 34 beta E12, p63—positive winding cords with a characteristic palisade arrangement of neoplastic cells in the periphery of the tumor. Based on these results, the cutaneous neoplasm was diagnosed as a trabecular trichoblastoma with spindle cells and rare structures resembling papillary mesenchymal bodies. Additionally, multiple enlarged sebaceous lobules clustered around dilated ducts suggestive of sebaceous gland hyperplasia were detected near the trichoblastoma. No PV DNA was found in the examined tissues, suggesting that ovine PVs are not involved in the pathogenesis of the present skin tumors with adnexal differentiation. Further investigations and efforts are required to elucidate the prevalence of skin tumors with adnexal differentiation in this species.

Examination of skin lesions in rats with induced hyperthyroidism and hypothyroidism

We investigated the pathogenesis of skin lesions due to hypothyroidism and hyperthyroidism in rats. We used 30 rats allocated into hypothyroidism, hyperthyroidism and control groups. Blood samples were evaluated for levels of thyroid stimulating hormone (TSH), tri-iodothyronine (T3) and thyroxine (T4). Skin samples were examined for melan-A, lymphatic vessel endothelial hyaluronic acid receptor 1 (LYVE1), cluster of differentiation 31 (CD31), protein gene product 9.5 (PGP9.5), calretinin, chromogranin, synaptophysin and pancytokeratin. Histopathological examination of the skin sections revealed thickened epidermis in the hyperthyroidism group due to an increased number of cells, and a decreased number of hair follicles and epithelial cell rows in the epidermis with an increased number of fat cells in the dermis of the rats in the hypothyroidism group. No significant difference was observed in the immunoreactions of pancytokeratin, PGP9.5, CD31 and synaptophysin among the groups. The hyperthyroidism and hypothyroidism groups exhibited a marked increase in melan-A immunoreaction. Expression of LYVE-1, chromogranin and calretinin was increased in the hyperthyroidism group and decreased in the hypothyroidism group. We found that melan-A, LYVE-1, chromogenin and calretinin play an important role in the pathogenesis of skin lesions caused by thyroid disorders.

Basaloid tumors arising from seborrheic keratosis: Malignant basal cell carcinoma or benign basaloid follicular hamartomatous proliferation?

BACKGROUND

Basaloid tumors arising from seborrheic keratosis (SK) that resembled basal cell carcinoma (BCC) were infrequently observed in our patients. They also exhibited morphologic features similar to those of trichoblastoma or basaloid follicular hamartoma.

METHODS

We retrospectively collected cases of SK with basaloid tumors from 2001 to 2017. Ten cases of BCC, five of nevus sebaceus with trichoblastoma, five of trichoblastoma, and five of trichoepithelioma were included as controls. Tumor-associated antigens Bcl-2, CD10, PHLDA1, and CK20 were tested. Antigenic markers CD34 and CD10 were used to analyze peritumoral stroma features and Ki-67 and pHH3 to measure the mitotic activity.

RESULTS

Ten cases of SK with basaloid tumors were found and all located in non-sun-exposed areas, including five men and five women, with a mean age of 61 years. A distinct PHLDA1 staining was not observed. The staining patterns of basaloid tumor lobules associated with SK were similar to the benign control group. Bcl-2 staining in the tumor lobules was mostly negative. Peritumoral CD10 stain and CK20-positive Merkel cells in the lobules were observed and the mitotic counts were low.

CONCLUSION

Basaloid tumors arising from SK are not always BCC. They were all benign follicular hamartomatous proliferation in this case series.

Alginate microparticles loaded with basic fibroblast growth factor induce tissue coverage in a rat model of myelomeningocele

BACKGROUND/PURPOSE

We sought to develop a minimally invasive intra-amniotic therapy for prenatal treatment of myelomeningocele (MMC) in an established rat model.

METHODS

Time-dated pregnant rats were gavage-fed retinoic acid to induce MMC. Groups received intraamniotic injections at E17.5 with alginate particles loaded with fluorescent dye, basic fibroblast growth factor (Alg-HSA-bFGF), fluorescently tagged albumin (Alginate-BSA-TR), free bFGF, blank alginate particles (Alg-Blank), or PBS. Groups were analyzed at 3 h for specific particle binding or at term (E21) to determine MMC coverage.

RESULTS

Alginate microparticles demonstrated robust binding to the MMC defect 3 h after injection. Of those specimens analyzed at E21, 150 of 239 fetuses (62.8%) were viable. Moreover, 18 of 61 (30%) treated with Alg-HSA-bFGF showed evidence of soft tissue coverage compared to 0 of 24 noninjected (P = 0.0021), 0 of 13 PBS (P = 0.0297), and 0 of 42 free bFGF (P = P < 0.0001). Scaffolds of aggregated particles associated with disordered keratinized tissue were observed covering the defect in 2 of 18 (11%) Alg-BSA-TR and 3 of 19 (16%) Alg-Blank specimens.

CONCLUSIONS

Injection of microparticles loaded with bFGF resulted in significant soft tissue coverage of the MMC defect compared to controls. Alginate microparticles without growth factors might result in scaffold development over the fetal MMC.

TYPE OF STUDY

Basic science.

LEVEL OF EVIDENCE

N/A.

A case report of a primary apocrine adenocarcinoma of the eyelid with literature review

INTRODUCTION

Primary Apocrine adenocarcinomas (PAA) are very infrequent tumors that are often confused initially with benign lesions. Little is known about this disease and there is still much to be clarified. We present a case of PAA on the eyelid successfully treated with surgery alone and a literature review regarding what is currently described about this disease.

METHODS

Noncomparative, retrospective case report of a patient with PAA on the eyelid succesfully treated with surgery alone and a literautre review.

RESULTS

A 91-year-old man with a 2 months lesion on the upper left eyelid was treated with surgery alone with oncological margins of 5mm. The Hystopathology diagnosis was a PAA of the eyelid and free margins were obtained. After 12 months of follow-up, the patient does not show any signs of local recurrence or distant metastasis. A review of the literature suggests these tumors are located more frequently in the axilla (50%) and secondly in the head and neck (35%), with similar distribution in the upper (41%) and lower eyelid (45%). The most commonly used treatment is surgical excision, but radiotherapy and chemotherapy have also been used with variable results.

CONCLUSIONS

PAA is a very rare and aggressive tumor. Because it is so infrequent, treatments are based on the sporadic cases encountered in the literature. As more cases are reported, more can be elucidated about the characteristics of this tumor, its behavior and best treatment choice and this may allow progress in the understanding and management of this disease.

Immunohistochemical Markers for Prospective Studies in Neurofibromatosis-1 Porcine Models

Neurofibromatosis type 1 (NF1) is a common, cancer-predisposing disease caused by mutations in the NF1 tumor gene. Patients with NF1 have an increased risk for benign and malignant tumors of the nervous system (e.g., neurofibromas, malignant peripheral nerve sheath tumors, gliomas) and other tissues (e.g., leukemias, rhabdomyosarcoma, etc.) as well as increased susceptibility to learning disabilities, chronic pain/migraines, hypertension, pigmentary changes, and developmental lesions (e.g., tibial pseudoarthrosis). Pigs are an attractive and upcoming animal model for future NF1 studies, but a potential limitation to porcine model research has been the lack of validated reagents for direct translational study to humans. To address that issue, we used formalin-fixed tissues (human and pigs) to evaluate select immunohistochemical markers (activated caspase-3, allograft inflammatory factor-1, beta-tubulin III, calbindin D, CD13, CD20, desmin, epithelial membrane antigen, glial fibrillary acidic protein, glucose transporter-1, laminin, myelin basic protein, myoglobin, proliferating cell nuclear antigen, S100, vimentin, and von Willebrand factor). The markers were validated by comparing known expression and localization in human and pig tissues. Validation of these markers on fixed tissues will facilitate prospective immunohistochemical studies of NF1 pigs, as well as other pig models, in a more efficient, reproducible, and translationally relevant manner.

Pleomorphic Adenoma of the Eyelid with Apocrine Gland Origin; an Atypical Location

Purpose:

To describe the clinical presentation and treatment of a patient with a cutaneous pleomorphic adenoma of the eyelid.

Case Report:

A 73-year-old male patient presented with a nodular mass on the lateral third of his right upper eyelid, which had slowly enlarged over 10 years. Radiologic features were of an extra-conical mass, with no invasion of adjacent structures. An excisional biopsy of the lesion was performed. The histopathological examination revealed a biphasic tumor, composed of tubules with a double layer of epithelial cells arranged in a chondromyxoid stroma. The inner epithelial cells were positive for pancytokeratins AE1/AE3 and carcinoembryonic antigen. The outer epithelial cells and stromal component expressed vimentin and S100 protein. These pathologic findings were consistent with a palpebral pleomorphic adenoma, with an apocrine gland origin.

Conclusion:

Pleomorphic adenomas of the skin are rare tumors, and even less frequent as tumors of the ocular adnexa. These lesions should be considered in the differential diagnosis of palpebral nodular masses, and complete excision should be attempted due to the possibility of malignant transformation.

Towards pain-free diagnosis of skin diseases through multiplexed microneedles: biomarker extraction and detection using a highly sensitive blotting method

Immunodiagnostic microneedles provide a novel way to extract protein biomarkers from the skin in a minimally invasive manner for analysis in vitro. The technology could overcome challenges in biomarker analysis specifically in solid tissue, which currently often involves invasive biopsies. This study describes the development of a multiplex immunodiagnostic device incorporating mechanisms to detect multiple antigens simultaneously, as well as internal assay controls for result validation. A novel detection method is also proposed. It enables signal detection specifically at microneedle tips and therefore may aid the construction of depth profiles of skin biomarkers. The detection method can be coupled with computerised densitometry for signal quantitation. The antigen specificity, sensitivity and functional stability of the device were assessed against a number of model biomarkers. Detection and analysis of endogenous antigens (interleukins 1α and 6) from the skin using the device was demonstrated. The results were verified using conventional enzyme-linked immunosorbent assays. The detection limit of the microneedle device, at ≤10 pg/mL, was at least comparable to conventional plate-based solid-phase enzyme immunoassays.

Muc5ac mucin expression during rat skin development

Some mucin genes have been detected during human embryonic and fetal organ development; however, little is known about mucin expression in epidermal development, neither in humans nor in other species. The present research was developed to explore Muc5ac skin expression during pre- and post-natal rat development. Immunohistochemistry (IHC), Western blotting (WB) and RT-PCR were employed. By IHC, Muc5ac protein was found early in embryonic epidermis from day 13 of gestation until seven days after birth when the surface epidermis became negative and the reaction was restricted to secreting sebum cells. In coincidence with IHC findings, WB analysis showed a band at approximately 200KDa at the same periods of development. Results were also confirmed by RT-PCR.

Muc5ac expression in rat embryonic epidermis suggests that Muc5ac may play a protective role in embryonic skin previous to birth which may be replaced by pile covering. To our knowledge, this is the first report that confirmed Muc5ac expression during skin development.