ARP-T1-associated Bazex-Dupré-Christol syndrome is an inherited basal cell cancer with ciliary defects characteristic of ciliopathies

Cholesterol in the ciliary membrane as a therapeutic target against cancer

Primary cilium is a non-motile, antenna-like structure that develops in the quiescent G0 phase-cell surface. It is composed of an array of axonemal microtubules polymerized from the centrosome/basal body. The plasma membrane surrounding the primary cilium, which is called the ciliary membrane, contains a variety of receptors and ion channels, through which the cell receives extracellular chemical and physical stimuli to initiate signal transduction. In general, primary cilia disappear when cells receive the proliferative signals to re-enter the cell cycle. Primary cilia thus cannot be identified in many malignant and proliferative tumors. In contrast, some cancers, including basal cell carcinoma, medulloblastoma, gastrointestinal stromal tumor, and other malignancies, retain their primary cilia. Importantly, it has been reported that the primary cilia-mediated oncogenic signals of Hedgehog, Wnt, and Aurora kinase A are involved in the tumorigenesis and tumor progression of basal cell carcinoma and some types of medulloblastoma. It has also been demonstrated that cholesterol is significantly more enriched in the ciliary membrane than in the rest of the plasma membrane to ensure Sonic hedgehog signaling. A series of epidemiological studies on statin drugs (cholesterol-lowering medication) demonstrated that they prevent recurrence in a wide range of cancers. Taken together, ciliary cholesterol could be a potential therapeutic target in primary cilia-dependent progressive cancers.

Multidisciplinary approach to Gorlin-Goltz syndrome: from diagnosis to surgical treatment of jawbones

Background

Gorlin syndrome, also known as Gorlin-Goltz syndrome (GGS) or basal cell nevus syndrome (BCNS) or nevoid basal cell carcinoma syndrome (NBCCS), is an autosomal dominant familial cancer syndrome. It is characterized by the presence of numerous basal cell carcinomas (BCCs), along with skeletal, ophthalmic, and neurological abnormalities. It is essential to anticipate the diagnosis by identifying the pathology through the available diagnostic tests, clinical signs, and radiological manifestations, setting up an adequate treatment plan.

Main body

In the first part, we searched recent databases including MEDLINE (PubMed), Embase, and the Cochrane Library by analyzing the etiopathogenesis of the disease, identifying the genetic alterations underlying them. Subsequently, we defined what are, to date, the major and minor clinical diagnostic criteria, the possible genetic tests to be performed, and the pathologies with which to perform differential diagnosis. The radiological investigations were reviewed based on the most recent literature, and in the second part, we performed a review regarding the existing jawbone protocols, treating simple enucleation, enucleation with bone curettage in association or not with topical use of cytotoxic chemicals, and “en bloc” resection followed by possible bone reconstruction, marsupialization, decompression, and cryotherapy.

Conclusion

To promote the most efficient and accurate management of GGS, this article summarizes the clinical features of the disease, pathogenesis, diagnostic criteria, differential diagnosis, and surgical protocols. To arrive at an early diagnosis of the syndrome, it would be advisable to perform radiographic and clinical examinations from the young age of the patient. The management of the patient with GGS requires a multidisciplinary approach ensuring an adequate quality of life and effective treatment of symptoms.

Multiple Basal Cell Carcinomas in Immunocompetent Patients

Simple Summary

It is widely known that long-term treatment with immunosuppressive drugs represents a risk factor for the onset of malignancies, including multiple basal cell carcinomas. However, multiple basal carcinomas are ao found in the general population, and even in the absence of specific predisposing genetic mutations. This paper aims, through the retrospective evaluation of all patients diagnosed and surgically treated for basal cell carcinomas during 5 years at our Dermatological Division, to identify the characteristics of these subjects and any possible risk factors, useful for outlining specific surveillance programs. In our experience, multiple carcinomas were identified in over 24% of the subjects analyzed, with several lesions removed, ranging from 2 to 11, confirming the relevance of this phenomenon.

Abstract

Background: The onset of multiple BCCs is a relatively common condition, not only among patients undergoing chronic treatment with immunosuppressant drugs, but also in the general population, although specific risk factors for immunocompetent patients have not been identified. A putative role of somatic mutations in the hedgehog pathway should be considered. Methods: This study is a retrospective observation of all patients diagnosed and surgically treated for BCCs during 5 years at our Dermatological Division. For these patients, we evaluated clinical and histopathological characteristics and data about possible risk factors for BCC. Results: Five-hundred and six patients affected by multiple BCCs, accounting for the 24.2% of the entire sample, have been identified. In these patients, the total number of BCCs was 1516, ranging from 2 to 11. Subjects affected by multiple BCCs were more frequently males, with an older age at diagnosis; multiple BCCs developed mainly on the trunk and were often represented by a nodular histotype. The multivariate analysis highlighted that male gender, older age, nodular BCC, or face involvement at the first diagnosis are risk factors for the development of multiple BCCs. Conclusions: The frequency of multiple BCCs even among the non-immunocompromised population underlines the need to subject patients to a close surveillance program, to allow early diagnosis and treatment of additional cancers.

HaCaT cells as a model system to study primary cilia in keratinocytes

Primary cilium (PC) is a microtubule‐based organelle found on the apical surface of most mammalian cell types, playing a role in development and tissue homeostasis. Ciliopathies are a rapidly growing group of human diseases characterized by disordered cilium. PC plays an important role in pathogenesis of basal cell cancer, the most common human malignancy. A significant increase in ciliation has been observed in the epidermis of atopic dermatitis and psoriasis patients. Spontaneously immortalized human keratinocytes, HaCaT are a model to study the epidermal homeostasis and pathophysiology. In contrast to what has been previously described, here, we show that HaCaT can be efficiently ciliated. In HaCaT cells, differentiation significantly increased the number of ciliated cells and we were able to analyse in detail the ciliary length progression with duration of differentiation. As the number of recognized ciliopathies continues to increase, the importance of ciliary models also rises. Even though keratinocytes do not become as highly and rapidly ciliated as cell lines frequently used in ciliary studies, they are a better model for the study of skin ciliopathies. Detailed progression of ciliation in HaCaT could serve as the basis for ciliary studies in this cell line.

Molecular pathology of skin adnexal tumours

AIMS

Tumours of the cutaneous adnexa arise from, or differentiate towards, structures in normal skin such as hair follicles, sweat ducts/glands, sebaceous glands or a combination of these elements. This class of neoplasms includes benign tumours and highly aggressive carcinomas. Adnexal tumours often present as solitary sporadic lesions, but can herald the presence of an inherited tumour syndrome such as Muir-Torre syndrome, Cowden syndrome or CYLD cutaneous syndrome. In contrast to squamous cell carcinoma and basal cell carcinoma, molecular changes in adnexal neoplasia have been poorly characterised and there are few published reviews on the current state of knowledge.

METHODS AND RESULTS

We reviewed findings in peer-reviewed literature on molecular investigations of cutaneous adnexal tumours published to June 2021.

CONCLUSIONS

Recent discoveries have revealed diverse oncogenic drivers and tumour suppressor alterations in this class of tumours, implicating pathways including Ras/MAPK, PI3K, YAP/TAZ, beta-catenin and nuclear factor kappa B (NF-κB). These observations have identified novel markers, such as NUT for poroma and porocarcinoma and PLAG1 for mixed tumours. Here, we provide a comprehensive overview and update of the molecular findings associated with adnexal tumours of the skin.