Keratin 17 mutation in pachyonychia congenita type 2 patient with early onset steatocystoma multiplex and Hutchinson-like tooth deformity

Expression patterns of keratin family members during tooth development and the role of keratin 17 in cytodifferentiation of stratum intermedium and stellate reticulum

Keratins are typical intermediate filament proteins of the epithelium that exhibit highly specific expression patterns related to the epithelial type and stage of cellular differentiation. They are important for cytoplasmic stability and epithelial integrity and are involved in various intracellular signaling pathways. Several keratins are associated with enamel formation. However, information on their expression patterns during tooth development remains lacking. In this study, we analyzed the spatiotemporal expression of keratin family members during tooth development using single-cell RNA-sequencing (scRNA-seq) and microarray analysis. scRNA-seq datasets from postnatal Day 1 mouse molars revealed that several keratins are highly expressed in the dental epithelium, indicating the involvement of keratin family members in cellular functions. Among various keratins, keratin 5 (Krt5), keratin 14 (Krt14), and keratin 17 (Krt17) are highly expressed in the tooth germ; KRT17 is specifically expressed in the stratum intermedium (SI) and stellate reticulum (SR). Depletion of Krt17 did not affect cell proliferation in the dental epithelial cell line SF2 but suppressed their differentiation ability. These results suggest that Krt17 is essential for SI cell differentiation. Furthermore, scRNA-seq results indicated that Krt5, Krt14, and Krt17 exhibited distinct expression patterns in ameloblast, SI, and SR cells. Our findings contribute to the elucidation of novel mechanisms underlying tooth development.

Steatocystoma multiplex of the scrotum. Clinical case

Steatocystoma multiplex is a disorder of the pilosebaceous unit characterized by multiple sebum-containing dermal cysts. We report the case of a 64-year-old male presented with multiple skin-colored, partially hyperemic cystic located in the scrotum area. They were accompanied by an active inflammatory process in the form of pain, swelling, hyperemia. The lesion was present for about 1 month. Previously, this patient had diagnosed with multiple steatocystoma located in the hip area and received surgical treatment.

At present, such reports in the scientific databases are presented sporadically, therefore we report on multiple steatocystoma of the scrotal localization due to its rarity.

[Benign skin neoplasms in children]

There are many different types of skin neoplasms in children and most are benign. Dermatologists should be able to differentiate between the various types of benign skin neoplasms and be able to recommend optimal treatment to concerned patients. Surgical removal of benign skin neoplasms is often the only treatment option. The aim of this paper is to provide a general overview of epidermal lesions (e.g., inflammatory linear verrucous epidermal nevus [ILVEN], nevus sebaceous), tumors of the epidermal appendages (e.g. pilomatrixoma), cutaneous neoplasms (e.g. angiofibroma), fibromatoses (e.g., knuckle pads), tumors comprised of fat, muscle, or bone tissue (e.g., osteoma cutis, subungual exostosis), epidermal cysts and pseudocysts, and pathologic fibrosis reactions after dermal injury (keloid). Scientific data are scarce and only in the last decade has it been possible to perform histopathological examinations and genetic studies together with detailed phenotyping to gain new understanding of the pathogenetic mechanisms.

Steatocystoma multiplex: A case report of a rare entity

Steatocystoma multiplex is an uncommon benign skin disease, which typically manifests as numerous intradermal cysts that can be scattered anywhere on the body. Although usually asymptomatic, it can be significantly disfiguring. One type of steatocystoma multiplex is known to be associated with the autosomal dominant inheritance of a mutation in the gene coding for keratin 17 (KRT17). In such cases, it is often concurrent with other developmental abnormalities of the ectoderm-derived tissues, such as the nails, hair, and teeth. To the best of our knowledge, few cases have been reported of steatocystoma multiplex of the oral and maxillofacial region. This report describes a case of steatocystoma multiplex of both sides of the neck and multiple dental anomalies, with a focus on its clinical, radiological, and histopathological characteristics, as well as the possibility that the patient exhibited the familial type of this condition.

Keratin 17 Promotes Lung Adenocarcinoma Progression by Enhancing Cell Proliferation and Invasion

Backgrounds

Lung adenocarcinoma (LAC) accounts for the majority of lung cancer, which is the leading cause of cancer-related mortality worldwide. Keratin 17 (KRT17) was reported to promote the tumor development of skin tumor and oral cancer. The aim of this study was to investigate the expression and function of KRT17 in LAC.

Material/Methods

Immunohistochemical staining and quantitative PCR were performed to explore the expression of KRT17 in both LAC tissues and adjacent normal liver tissues. Chi-square test, univariate analysis, and multivariate analysis were conducted to statistically evaluate the clinical significance of KRT17 in LAC. Proliferation, migration, and invasion capacities of LAC cells were assessed after overexpression or silencing KRT17.

Results

Both the RNA and protein levels of KRT17 were up-regulated in LAC tissues compared to normal lung tissues. High expression of KRT17 was correlated with advanced TNM stage and poor overall survival. Moreover, KRT17 was identified as a novel independent prognostic factor for LAC patients. Cellular studies showed that KRT17 can enhance the proliferation, migration, and invasion capacities of LAC cells, thereby promoting tumor progression.

Conclusions

High expression of KRT17 is frequent in LAC tissues, which promotes tumor proliferation and invasion, and is correlated with a poor overall survival. Targeting KRT17 may be a novel direction for LAC drug development.

Steatocystoma multiplex with hair shaft abnormalities

Steatocystoma multiplex (SM) is an unusual benign disorder of the pilosebaceous duct characterized by multiple cysts with little or no nail and hair involvement. We report a 30-year-old woman with multiple cystic nodules located on the neck, axillae and forearms as well as patchy scalp alopecia. Histopathological examination of the lesions was diagnostic of SM. Trichoscopy revealed pili torti and pili canaliculi. This patient represents an unusual clinical presentation of SM because of the presence of hair abnormalities.

Steatocystoma multiplex associated with bilateral preauricular sinuses

Steatocystoma multiplex is characterized by the development of numerous steatocystomas. The condition has occasionally been related to congenital bilateral preauricular sinuses. Herein, we present the third case of such an association, a 34-year-old male who was born with bilateral preauricular sinuses that were surgically repaired. When he was 14 years old, he presented with multiple steatocystomas on his forehead and temples, one of which was biopsied. There was no family history of the condition.

Comorbidities of hidradenitis suppurativa (acne inversa)

Comorbidities of hidradenitis suppurativa (acne inversa) were reviewed by extracting original and review publications included in MEDLINE, EMBASE and COCHRANE libraries using the terms "hidradenitis," "Verneuil" and "acne inversa." Follicular occlusion disorders, inflammatory bowel diseases, especially Crohn disease, spondylarthropathy, other hyperergic diseases, genetic keratin disorders associated with follicular occlusion and squamous cell carcinoma were the most common hidradenitis suppurativa comorbid diseases. A first classification of these major comorbidities and their possible genetic background reveals a list of chromosome loci and genes, which could be hidradenitis suppurativa candidates. Most of these diseases belong to the group of autoinflammatory disorders, where th17 cell cytokines seem to play a central role.

Pachyonychia congenita type 2, N92S mutation of keratin 17 gene: clinical features, mutation analysis and pathological view

Pachyonychia congenita (PC) type 2 is a rare inherited genetic disease characterized by hypertrophic nail dystrophy, palmoplantar hyperkeratosis and multiple pilosebaceous cysts. In some cases, natal teeth and hair abnormalities may be present. It is caused by mutations in keratin 17 or its expression partner keratin 6b. Here, an N92S (p.Asn92Ser) germline keratin 17 gene mutation in a pachyonychia congenita type 2 female patient is presented. The pedigree includes the 15 members of a family who showed a severe expression of the phenotype for six generations with a similar clinical picture consisting of sebaceous cysts, nail dystrophy, hyperkeratosis, hair abnormalities, natal teeth, hoarseness and hyperhydrosis. In conclusion, we emphasize the importance of diagnosing and managing pachyonychia congenita in childhood for the assistance of affected children and for the development of potential therapies.