Malignant Transformation Research Articles

Upregulated DNMT3a coupling with inhibiting p62-dependent autophagy contributes to NNK tumorigenicity in human bronchial epithelial cells

NNK, formally known as 4-(methyl nitrosamine)-1-(3-pyridyl)-1-butanoe, is a potent chemical carcinogen prevalent in cigarette smoke and is a key contributor to the development of human lung adenocarcinomas. On the other hand, autophagy plays a complex role in cancer development, acting as a "double-edged sword" whose impact varies depending on the cancer type and stage. Despite this, the relationship between autophagy and NNK-induced lung carcinogenesis remains largely unexplored. Our current study uncovers a marked reduction in p62 protein expression in both lung adenocarcinomas and lung tissues of mice exposed to cigarette smoke. Interestingly, this reduction appears to be contingent upon the activity of extrahepatic cytochrome P450 (CYP450), revealing that NNK metabolic activation by CYP450 enzyme escalates its potential to induce p62 downregulation. Further mechanistic investigations reveal that NNK suppresses autophagy by accelerating the degradation of p62 mRNA, thereby promoting the malignant transformation of human bronchial epithelial cells. This degradation process is facilitated by the hypermethylation of the Human antigen R (HuR) promoter, resulting in the transcriptional repression of HuR - a key regulator responsible for stabilizing p62 mRNA through direct binding. This hypermethylation is triggered by the activation of ribosomal protein S6, which is influenced by NNK exposure and subsequently amplifies the translation of DNA methyltransferase 3 alpha (DNMT3a). These findings provide crucial insights into the nature of p62 in both the development and potential treatment of tobacco-related lung cancer.

Gingival Proliferative Verrucous Leukoplakia and Cancer: A Systematic Review With Meta-Analysis.

Proliferative verrucous leukoplakia (PVL) is an oral potentially malignant disorder. Forms that affect only one tissue are poorly studied, especially the exclusively gingival PVL (gPVL), which may have a more increased malignant transformation potential. The aim of the present study was to characterise the gPVL and its risk of malignant transformation to better raise awareness of this specific disorder. The systematic review was performed on PubMed, Scopus, Web of Science and Google Scholar. Only articles reporting primary studies, case reports and case series were included. The meta-analysis was performed for the cancer prevalence, proportion of smokers, age and sex ratio, recurrences of gPVL and mortality. A total of 1298 studies were assessed for eligibility by reading titles and abstracts. Fourteen original articles were included with a total of 58 patients. The malignant transformation rate of gPVL was 47.75%. The mortality was 5.84%. The mean follow-up duration before malignant transformation was 3 years. gPVL seems to have a faster malignant transformation rate than the other forms of PVL. Finding anatomo-pathological or genetic markers could be a line of research to predict gPVL malignant transformation and improve its diagnosis and treatment.

Distinct copy number signatures between residual benign and transformed areas of carcinoma ex pleomorphic adenoma

The mechanisms involved with the pathogenesis of carcinoma ex pleomorphic adenoma (CXPA) seem to be associated with the accumulation of molecular alterations in the pleomorphic adenoma (PA). In this sense, using array-based comparative genomic hybridization (aCGH) a rare series of 27 cases of CXPA and 14 residual PA (rPA) adjacent to the transformation area, we investigated the profile of the copy number alterations (CNAs) comparing benign residual and transformed areas. The main findings were correlated with the histopathological classification by histologic subtype and degree of invasion. The distribution of losses (p = 0.187) and amplifications (p = 0.172) was not statistically different between rPA and CXPA. The number of gains was increased in the transformed areas compared to the benign residual areas (p = 0.005). PLAG1 gain was maintained along the malignant transformation, as it was observed in both residual PA and CXPA samples, likely being an earlier event during transformation. The amplification of GRB7 and ERBB2 may also be an initial step in the malignant transformation of PA to CXPA (salivary duct carcinoma subtype). Furthermore, the amplification of HMGA2 and RPSAP52 were the most prevalent alterations among the studied samples. It was noteworthy that amplified genes in the transformed areas of the tumors were enriched for biological processes related to immune signaling. In conclusion, our results underscored for the first-time crucial CNAs in CXPA, some of them shared with the residual benign area adjacent to the transformation site. These CNAs included PLAG1 gain, as well as amplification of GRB7, ERBB2, HMGA2, and RPSAP52.

Uveal melanoma: molecular-genetic mechanisms of arising and the therapeutic approaches

Uveal melanoma (UM) is a tumor of neuroectodermal origin, which results from malignant transformation of melanocytes of the eye vasculature: iris, ciliary body and chorioidea. UM represents up to 5% of all melanoma cases, but it is extremely aggressive, since half of patients with UM develop metastases within the first 1‒2 years after the tumor appearance. Molecular mechanisms of uveal melanoma carcinogenesis are poorly understood, and have already been shown to be different from those of skin melanoma. Activating mutations in the GNAQ and GNA11 genes, encoding the large G protein subunits Gq and G11, respectively, are found in 90% of UM patients. The main signaling cascade leading to the transformation of melanocytes of the uveal tract is the signaling pathway Gaq/PKC/MAPK, and the major regulators of this cascade are targets for the development of drugs. The development of the metastatic form of UM is most often associated with mutations in the genes BAP1, EIF1AX, GNA11, GNAQ, and SF3B1. A combination of a commercial expression test panel of 15 genes and a mutation panel of 7 genes, supplemented with data on the size of the primary tumor, has been shown to be highly effective prognostic signature in prediction the risk of metastases. The risk of metastases determines the choice of therapy and patient follow-up regimen. At the same time, no systemic therapy for the treatment of metastatic UM has been developed to date; new drugs undergoing clinical trials mostly refer to either targeted therapy aimed at inhibiting the protein products of mutant genes, or immunotherapy designed to stimulate an immune response against specific antigens. In addition to these approaches, the review also considers potential therapeutic targets of epigenetic regulation of UM development.

A Deep Learning System to Predict Epithelial Dysplasia in Oral Leukoplakia

Oral leukoplakia (OL) has an inherent disposition to develop oral cancer. OL with epithelial dysplasia (OED) is significantly likely to undergo malignant transformation; however, routine OED assessment is invasive and challenging. This study investigated whether a deep learning (DL) model can predict dysplasia probability among patients with leukoplakia using oral photographs. In addition, we assessed the performance of the DL model in comparison with clinicians’ ratings and in providing decision support on dysplasia assessment. Retrospective images of leukoplakia taken before biopsy/histopathology were obtained to construct the DL model (n = 2,073). OED status following histopathology was used as the gold standard for all images. We first developed, fine-tuned, and internally validated a DL architecture with an EfficientNet-B2 backbone that outputs the predicted probability of OED, OED status, and regions-of-interest heat maps. Then, we tested the performance of the DL model on a temporal cohort before geographical validation. We also assessed the model’s performance at external validation with opinions provided by human raters on OED status. Performance evaluation included discrimination, calibration, and potential net benefit. The DL model achieved good Brier scores, areas under the curve, and balanced accuracies of 0.124 (0.079–0.169), 0.882 (0.838–0.926), and 81.8% (76.5–87.1) at testing and 0.146 (0.112–0.18), 0.828 (0.792–0.864), and 76.4% (72.3–80.5) at external validation, respectively. In addition, the model had a higher potential net benefit in selecting patients with OL for biopsy/histopathology during OED assessment than when biopsies were performed for all patients. External validation also showed that the DL model had better accuracy than 92.3% (24/26) of human raters in classifying the OED status of leukoplakia from oral images (balanced accuracy: 54.8%–79.7%). Overall, the photograph-based intelligent model can predict OED probability and status in leukoplakia with good calibration and discrimination, which shows potential for decision support to select patients for biopsy/histopathology, obviate unnecessary biopsy, and assist in patient self-monitoring.

Secondary Chondrosarcoma of the Rib in a Case of Diaphyseal Aclasis: A Rare Case Report

Hereditary multiple exostosis has a 3%–5% chance of converting into chondrosarcoma. It is a rare case report of a 32-year-old female with hereditary multiple exostosis who presented with pain and progressive swelling over her right chest wall for 3 months. A clinical examination revealed a large globular swelling over her right chest. Imaging revealed a large, ill-defined, aggressive, and exophytic lesion with a thick cartilage cap arising from the 8th rib. The lesion was hypermetabolic and avid on PET CT scan. She underwent a core needle biopsy which showed features of malignant transformation. En-bloc resection of the tumor with 7, 8, and 9 ribs followed by plate and mesh reconstruction was carried out.

Application of a Photothermal Microscope To Study the Process of Cutaneous Lesion Formation of Malignant Melanoma.

In this study, we applied a photothermal microscope to study the process of malignant melanoma formation. We analyzed benign papilloma tumors, their metastatic carcinomas, and metastatic melanoma on the preparation of mouse skin using a gray-level co-occurrence matrix (GLCM) method. Based on the analysis of nine GLCM parameters investigated, the characteristics during the degenerative and metastatic processes are clarified by the investigation. The determination of characteristic parameters corresponding to three processes before, during, and after the degeneration indicated that this investigation enables the detection of the malignant transformation and related processes.

Evolution of the doctrine of Zollinger-Ellison syndrome. Literature review

Zollinger–Ellison syndrome (ZES) is a rare pathology that does not have specific clinical manifestations and is not always diagnosed in time. This is attributed to doctors’ insufficient awareness of this pathology and the limited availability of the necessary examination methods. Foreign literary sources on this problem are analysed. Historical data regarding the discovery of this pathology and the origin of the syndrome’s name are provided. The epidemiology of the disease is highlighted. The most characteristic clinical manifestations and possible complications of ZES are described in detail. The characteristic changes in gastric acid production associated with this pathology and their diagnostic value (sensitivity and specificity) are presented. At the same time, indicators of both basal and maximal stimulated gastric acid production are significantly increased. The most important stage in the examination of patients with suspected ZES is the determination of blood gastrin levels. At the same time, it is shown that it is not always possible to make definitive judgements in support of ZES based on gastrin indicators. An absolute criterion in favor of ZES is fasting gastrin values of 1000 pg/ml or more. When gastrin levels are less than this indicator, tests using secretin or calcium gluconate have significant diagnostic value. In these circumstances, tests with secretin or calcium gluconate are mandatory. The information on the possible localization of gastrin, the incidence of malignant transformation, and the mechanism of metastasis is given. Methods of determining gastrin localization, sensitivity, and specificity are described in detail. Based on the findings, a differentiated treatment strategy for patients with ZES is provided. Indications and contraindications for surgical and medical treatment of patients with ZES are given. The prospects of a new treatment direction ‑ the use of targeted radiotherapy ‑ are shown. These patients require constant monitoring by a gastroenterologist and a surgeon and periodically undergo the necessary examinations.

GlycoSS: A DNA Glycosignal Sieve for Deciphering Spatially Resolved EpCAM-Specific Glycoforms.

Malignant transformation of cancer is often accompanied by aberrant glycopatterns. Epithelial-mesenchymal transition (EMT) is a crucial biological process in cancer migration and invasion, accelerating cancer deterioration. High-precision analysis of protein-glycan spatial profiling in the EMT process is essential for elucidating glycosylation functions and cancer progression. However, the diversity of glycans in composition and conformation complicates their spatial analysis. Here, we develop a DNA glycosignal sieve (GlycoSS) visualization platform for screening glycoform expression with a protein spatial dimension. GlycoSS utilizes protein-anchored DNA nanoscanners of distinct lengths to control glycosignal readout, enabling protein-glycan distance modulations, and simultaneously orthogonally amplify glycoform output through signal amplification by an exchange reaction. Using GlycoSS, we screened EpCAM-specific hypoglycosylated glycoform signals in different breast cancer cell subtypes, especially characterizing the spatial distribution of glycans on the MCF-7 cell surface. Considering that the EpCAM-specific N-glycan dysregulation in EMT is pivotal, GlycoSS revealed dynamic glycan fluctuations during IGF-1-induced EMT, revealing that the N-glycans were positively associated with tumor malignancy and metastasis. GlycoSS is anticipated to accelerate the identification of aberrant N-glycosylation in tumor progression, advancing systemic glycobiology insights. Notably, GlycoSS is capable of analyzing diverse glycoprotein profiles, offering additional dimensions into the role of glycoprotein nanoenvironments in regulating membrane protein function.

Small cyst size and lack of growth as negative predictors of malignant transformation in low-risk intraductal papillary mucinous neoplasms of the pancreas: A systematic review and meta-analysis.

For branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs) without worrisome features (WFs) or high-risk stigmata (HRS), current guidelines recommend surveillance. However, these intraductal papillary mucinous neoplasm (IPMNs), especially the small and stable-sized ones, carry a low risk of malignant transformation. Our aim was to assess whether small cyst size and absence of rapid growth provide reassurance against the development of WFs/HRS and malignancy (high-grade dysplasia (HGD) or pancreatic cancer (PC)). PubMed/Medline, Embase, the Cochrane Library and the Web of Science Core Collection were systematically searched from inception to May 2023 to identify studies investigating surveillance outcomes of low-risk BD-IPMNs. Studies assessing baseline cyst size and/or growth in relation to WFs/HRS and/or HGD/PC were included. The Newcastle-Ottawa scale tool was used to assess study quality. Of the 1937 identified manuscripts, 21 studies were eligible for inclusion. The quality of these studies was considered reasonable. A negative association between cyst size and WFs/HRS development was found in 11 out of 13 relevant studies, but only one out of nine studies reported a negative association between size and malignancy. Regarding cyst growth, four out of six studies described a negative association with the development of WFs/HRS, and all six reported a negative association with malignancy. The pooled relative risk (RR) of developing WFs/HRS or malignancy for cysts ≤15mm was 0.37 (95% CI 0.25-0.57) and the RR of developing malignancy for cyst growth <2-2.5mm/year was 0.04 (95% CI 0.02-0.09)). This systematic review and meta-analysis shows that small and stable-sized low-risk BD-IPMNs are associated with a markedly low progression rate, with stable cyst size being the most reassuring feature. Because of substantial heterogeneity in definitions and reported outcome measures, prospective studies are needed to confirm that surveillance of small and stable sized cyst can be de-intensified or even discontinued.

Pre-ciliated tubal epithelial cells are prone to initiation of high-grade serous ovarian carcinoma

The distal region of the uterine (Fallopian) tube is commonly associated with high-grade serous carcinoma (HGSC), the predominant and most aggressive form of ovarian or extra-uterine cancer. Specific cell states and lineage dynamics of the adult tubal epithelium (TE) remain insufficiently understood, hindering efforts to determine the cell of origin for HGSC. Here, we report a comprehensive census of cell types and states of the mouse uterine tube. We show that distal TE cells expressing the stem/progenitor cell marker Slc1a3 can differentiate into both secretory (Ovgp1+) and ciliated (Fam183b+) cells. Inactivation of Trp53 and Rb1, whose pathways are commonly altered in HGSC, leads to elimination of targeted Slc1a3+ cells by apoptosis, thereby preventing their malignant transformation. In contrast, pre-ciliated cells (Krt5+, Prom1+, Trp73+) remain cancer-prone and give rise to serous tubal intraepithelial carcinomas and overt HGSC. These findings identify transitional pre-ciliated cells as a cancer-prone cell state and point to pre-ciliation mechanisms as diagnostic and therapeutic targets.

6590 Androgen Derived Hepatocellular Adenoma And Reinitiation Of Gender Affirming Hormone Therapy

Abstract Disclosure: A.L. McKenna: None. Y. Huang: None. L. Yang: None. N. Loo: None. C. Ritchie: None. A. Metcalfe: None. R. Nakhleh: None. M. Krishna: None. S. Thota-Kammili: None. J. Eleazer: None. A.Y. Chang: None. Hepatocellular adenomas (HCA) are uncommon, benign epithelial tumors of the liver. Risk factors include exogenous estrogen or androgen use, and genetic and metabolic syndromes. Management of HCA is delineated by sex assigned at birth; Observation is recommended in an HCA less than 5 cm in an individual assigned female at birth, while resection of an HCA in an individual assigned male at birth is recommended no matter the size due to risk of malignant transformation. What is not known is whether risk is different for individuals with gender incongruence on gender affirming hormone therapy (GAHT). There is limited data on the risk of HCA in this population. One case report of a transgender man who continued GAHT after diagnosis of an HCA though no follow-up information was available. We present follow-up on a transgender man assigned female at birth with multiple hemorrhagic HCA that was re-initiated on GAHT after stabilization of adenomas off GAHT. Unlike prior cases, the molecular profile showed ß-catenin negative, estrogen and androgen receptors positive. This is the first case report to our knowledge reporting detailed follow-up after restarting masculinizing GAHT after diagnosis of HCA. A 24-year-old transgender man presented to the emergency department with right upper quadrant pain. Initial labs were notable for ALT of 239 units per liter (U/L) and AST 165 U/L. Magnetic resonance imaging (MRI) of the abdomen and liver elastogram revealed multiple bilobar hepatic masses, the largest measuring 9.9 cm concerning for hemorrhagic HCA which was subsequently confirmed on liver biopsy. Immunostains were positive for estrogen and androgen receptors. The patient had no history of alcohol or illicit drug use, tattoos, or family history of liver disease. The patient had been treated with 100 mg of intramuscular testosterone cypionate weekly for the past six years for gender incongruence locally. No testosterone concentrations were available from prior to or during acute presentation. Discontinuation of hormone therapy was recommended along with conservative management with frequent MRI. Over the next 19 months, monitoring revealed improvement/resolution of the auto infarcting adenomas with the last MRI noting two stable HCA measuring 2.1 cm and 0.8 cm without new or enlarging liver lesions. Due to gender dysphoria off GAHT, reinitiation of hormone therapy with low dose AndroGel 1.62% topically was prescribed at 18 months after presentation. The patient has been monitored with labs monthly and plans to obtain MRI abdomen every three months. To date, the patient has tolerated reinitiation of therapy. This case demonstrates that patients on masculinizing GAHT who develop HCA can be conservatively managed and monitored based on pathology and that testosterone does not necessarily explain sex differences in the presentation/malignant transformation of HCA cisgender men as opposed to cisgender women. Presentation: 6/3/2024

7446 Primary Adrenal Mature Teratoma Initially Diagnosed As An Adrenal Myelolipoma

Abstract Disclosure: A. White-Cotsmire: None. B. Kodali: None. A.M. Avram: None. S.S. Shah: None. Background: Teratomas are a type of germ cell tumor containing different types of tissue (e.g., hair, teeth, bone adipose, muscle). Most teratomas are benign (i.e., mature), but they may also be malignant (i.e., immature). Both immature and mature teratomas contain derivatives of ectoderm, endoderm, and mesoderm; however, immature teratomas are differentiated by the presence of embryonic, usually neuroectodermal, tissue. Mature teratomas have the potential for malignant transformation (1–2% of cases), usually squamous cell carcinoma within the teratoma. Extra-gonadal teratomas are rare (only 1–5%); reported locations include sacrococcygeal, head and neck, retroperitoneum, mediastinum, brain and spine, liver, and rarely adrenal glands. (1) Only 18 cases of adult primary adrenal teratomas have been reported since 1952. (2)Clinical Case: A 48-year-old woman with 4 days of worsening abdominal pain underwent CT imaging, which demonstrated a 6cm complex left adrenal mass containing peripheral and scattered internal-coarse calcifications with internal soft tissue and fat components, suggestive of adrenal myelolipoma with probable sequela of previous hemorrhage. Subsequent endocrine follow-up ruled out a cortisol secreting tumor with a negative dexamethasone suppression test and pheochromocytoma with normal serum free metanephrines and normetanephrines. Dedicated adrenal protocol CT scan further characterized the mass as a mature adrenal teratoma containing a rudimentary mandible and two teeth within the soft tissue associated with internal microscopic fat. The left renal vein was anteriorly displaced by this left adrenal mass and severely narrowed by the large adrenal mass, with development of left retroperitoneal collateral venous drainage from the left kidney into the lumbar venous system. The patient opted for conservative management with active clinical surveillance. Conclusion: This is a rare case of adrenal mature teratoma in an adult, originally diagnosed as an adrenal myelolipoma. This case highlights the use of more dedicated adrenal imaging for the characterization of adrenal tumors and the broad differential of benign non-functional adrenal tumors, including myelolipomas, lipomas, angiomyolipomas, and nonfunctional adenomas. However, a definitive diagnosis can only be confirmed by surgical removal of the tumor, usually through a laparoscopic approach, with histopathologic evaluation.

A presentation of basal cell adenoma: a case report

BackgroundWhile statistically rare in comparison to other head and neck tumours, parotid gland swellings are often encountered in clinical practice where one of the primary goals of examination becomes distinction between benign and malignant lesions. Hallmarks of malignancy are characterized by a female preponderance, history of radiation exposure, a positive family history, and clinical features like heterogenous consistency, fixity to skin/underlying tissues and involvement of facial nerve.Case presentationHere we present a case of parotid swelling in a 72-year old gentleman from south India that had a curious amalgamation of both benign and malignant features.ConclusionsWhile benign, the risk of malignant transformation and rare multicentric occurrence indicates a need to keep basal cell adenoma in mind in case of parotid swellings and their surgical management.

8034 Putting the Pieces Together: Carney Complex, A Hyper-Rare Congenital Neoplastic Syndrome

Abstract Disclosure: G. Fontanazza: None. A.R. Conforti: None. K. Bird: None. M. Caplan: None. Intro: Carney complex (CNC) is an autosomal dominant disorder characterized by multisystem neoplasia that primarily affects the thyroid, pituitary, and adrenal glands. Its prevalence is not well established, as only 750 cases have been reported worldwide. This condition arises when an inactivating PRKAR1A gene mutation results in dysregulated cell proliferation and tumorigenesis. Complications include the potential for malignant transformation and systemic manifestations, necessitating comprehensive management and ongoing surveillance of disease progression. Case: The patient is a 58-year-old woman who initially presented as a teenager with complaints of hirsutism, truncal obesity, and violaceous abdominal striae. Initial workup revealed a low-dose dexamethasone suppression test that resulted in a non-suppressed cortisol levels. She also had undetectable adrenocorticotropic hormone (ACTH) levels. Imaging revealed no pituitary masses and demonstrated slight bilateral adrenal enlargement without adenomas. Despite these results, she was empirically treated for presumed pituitary-dependent Cushing's disease and received external beam radiation. Despite treatment, she continued to have episodes of hypercortisolism that were apparent clinically and biochemically. Over time, she developed a cardiac myxoma with six cerebrovascular accidents and multiple benign tumors. As an adult, she underwent extensive endocrine evaluation, which revealed urine cortisol excretion that paradoxically rose in response to dexamethasone. ACTH levels were always undetectable, even when she was significantly hypercortisolemic. Genetic testing revealed a homozygous mutation in the melanocortin-2 receptor (MC2R). Accordingly, she elected to have a bilateral adrenalectomy and was started on hydrocortisone and fludrocortisone. Discussion: The patient exhibited ACTH-independent micronodular adrenal hyperplasia and its most frequent variant, primary pigmented nodular adrenocortical disease. Bilateral pigmented nodular hyperplasia is a finding which can occur in association with CNC and cause episodic hypercortisolism. These patients have been shown to respond to dexamethasone with a paradoxical increase in glucocorticoid excretion. While management requires ongoing surveillance, this patient had not been diagnosed until later in life and did not have regular screening. When speculating on the late detection, her story reflects the parable of the blind men and the elephant: endocrinology managed Cushing's disease, cardiology managed atrial myxoma, and oncology managed osteochondromyxomas. Limited perspective with specialized management and an inability to see the whole picture led to prolonged diagnosis with unfortunate sequelae. This report encourages physicians to develop perspective awareness and to consider the entire picture when treating patients. Presentation: 6/2/2024

Epidemiology and tumor microenvironment of ocular surface and orbital tumors on growth and malignant transformation.

The ocular surface and orbit constitute unique microenvironments in the human body. Current advances in molecular research have deepened our understanding of tumor development in these regions. Tumors exhibit greater heterogeneity compared to normal tissues, as revealed by pathological and histological examinations. The tumor microenvironment (TME) plays a crucial role in the proliferation and progression of cancer cells. Factors from the external environment or the body's own inflammation and microcirculation interact within the TME, maintaining a delicate balance. Disruption of this balance, through uncontrolled signal pathway activation, can transform normal or benign tissues into malignant ones. In recent years, various systemic immunotherapies have been developed for cancer treatment. This study reviews the epidemiology of ocular surface and orbital tumors include squamous cell carcinoma, basal cell carcinoma, sebaceous carcinoma and lymphoma in conjunction with their occurrence, growth, and underlying mechanisms. We propose that by examining clinical histopathological images, we can identify specific and shared microscopic features of tumors. By collecting, classifying, and analyzing data from these clinical histopathological images, we can pinpoint independent diagnostic factors characteristic of tumors. We hope this study provides a basis for future exploration of the mechanisms underlying different ocular diseases.

Calcineurin-mediated dephosphorylation stabilizes E2F1 protein by suppressing binding of the FBXW7 ubiquitin ligase subunit

The transcription factor E2F1 serves as a regulator of the cell cycle and promotes cell proliferation. It is highly expressed in cancer tissues and contributes to their malignant transformation. Degradation by the ubiquitin-proteasome system may help to prevent such overexpression of E2F1 and thereby to suppress carcinogenesis. A detailed understanding of the mechanisms underlying E2F1 degradation may therefore inform the development of new cancer treatments. We here identified SCFFBXW7 as a ubiquitin ligase for E2F1 by comprehensive analysis. We found that phosphorylation of E2F1 at serine-403 promotes its binding to FBXW7 (F-box/WD repeat-containing protein 7) followed by its ubiquitination and degradation. Furthermore, calcineurin, a Ca2+/calmodulin-dependent serine-threonine phosphatase, was shown to stabilize E2F1 by mediating its dephosphorylation at serine-403 and thereby preventing FBXW7 binding. Treatment of cells with Ca2+ channel blockers resulted in downregulation of both E2F1 protein and the expression of E2F1 target genes, whereas treatment with the Ca2+ ionophore ionomycin induced upregulation of E2F1. Finally, the calcineurin inhibitor FK506 attenuated xenograft tumor growth in mice in association with downregulation of E2F1 in the tumor tissue. Impairment of the balance between the opposing actions of FBXW7 and calcineurin in the regulation of E2F1 abundance may therefore play an important role in carcinogenesis.

Comprehensive transcriptomic analysis identifies three distinct subtypes of pituitary adenomas: insights into tumor behavior, prognosis, and stem cell characteristics

BackgroundPituitary adenomas (PAs) are the second most common intracranial tumor. While current diagnostic practices rely primarily on histological testing, they often fail to capture the molecular complexities of pituitary adenomas, underscoring the need for a molecular-based classification to refine therapeutic strategies and prognostic assessments. This study aims to provide a molecularly unbiased classification of pituitary adenomas and explore their unique gene expression patterns and clinical features.MethodsWe performed unsupervised hierarchical clustering of the gene expression profiles of 117 PA samples to identify three distinct molecular subtypes. Subsequently, we analyzed the compiled transcriptomic profiles of each individual subtype for pathway enrichment. We also validated the new classification with a validation set containing 158 PAs and 24 pituitary adenoma stem cells (PASCs).ResultsConsensus clustering of transcriptomic data from 117 pituitary adenoma (PA) samples identified three distinct molecular subtypes, each showing unique gene expression patterns and associated biological processes: Group I is enriched in signaling pathways, such as the cAMP signaling pathway and the calcium signaling pathway. Group II is primarily related to metabolic processes, including nitrogen metabolism and arginine biosynthesis in cancer. Group III predominantly shows enrichment in immune responses and potential malignant transformation of the disease, especially through cancer-related pathways such as the JAK–STAT signaling pathway and the PI3K–Akt signaling pathway. The immune profiling revealed distinct patterns for each subtype: Group I had higher dendritic cells and fewer CD8+ T cells, Group II had more monocytes and macrophages, and Group III had elevated levels of T cells. Additionally, there were differences in clinical characteristics and prognosis among the subtypes, with Group III having a worse prognosis, despite the smaller tumor size compared to other groups. Notably, differences in PASCs correlated with the molecular subtypes, with Group III stem cells being enriched in tumorigenesis pathways, PI3K–Akt signaling pathway and Ras signaling pathway.ConclusionOur study introduces a novel molecular classification for pituitary adenomas, independent of traditional histological methods. Each subtype features distinct genetic, molecular, and immunological profiles. We have isolated pituitary adenoma stem-like cells (PASCs), pairing them with tumor tissues for detailed transcriptomic analysis. These PASCs exhibit diverse molecular traits consistent with the new classification.

A Challenging Case Of Giant Maxillary Ameloblastoma: Navigating Rarity And Complexity In Diagnosis And Treatment

Background: Ameloblastoma is a rare, aggressive, benign odontogenic tumor that most commonly occurs in the jaw. Maxillary occurrences are rarely reported. Case Presentation: We report the case of a 61-year-old male presenting with right-sided unilateral nasal obstruction, characterized by a mass occupying the entire right nasal fossa upon anterior rhinoscopy. A computed tomography (CT) scan, combined with magnetic resonance imaging (MRI), revealed a locally advanced mass centered on the right maxillary sinus. The patient underwent wide excision of the mass, and histopathological analysis confirmed the diagnosis of ameloblastoma. Discussion: Naso-sinus ameloblastomas are rare, benign, and slow-growing tumors, accounting for approximately 0.11% of nasal and sinus tumors. More common in men, they typically present between the ages of 20 and 30. Symptoms include nasal obstruction and epistaxis, with occasional facial swelling or headaches. These tumors often originate in the posterior maxillary region and extend into the maxillary sinuses and nasal cavity. Diagnosis is facilitated by imaging, where the tumors appear as solid, radio-opaque masses. Radical surgical resection is the preferred treatment, as it is essential for preventing recurrence. The prognosis is generally favorable, with no documented cases of malignant transformation or metastasis, and recurrences are rare when appropriate surgical management is performed. Conclusion: Medical imaging plays a crucial role in diagnosis and allows for the evaluation of tumor dissemination and anatomical involvement. The treatment of maxillary ameloblastoma typically involves surgical excision, with the complexity of management often linked to the extent of tumor spread.

Thyroglossal Duct Cyst Carcinoma: Our 12-year Experience in a Tertiary Care Centre.

Malignant transformation in thyroglossal duct cyst is an extremely rare occurrence, papillary carcinoma being the most common type of malignancy. In this study, we present our 12-years experience on this rare pathology. Records of all the patients with thyroglossal duct cyst and thyroid malignancies who were managed between January 2011 and December 2022 were reviewed retrospectively. The data was recorded and studies. Descriptive statistics were used to summarize the data. Out of 112 cases of thyroglossal duct cyst, 11 adult patients had associated carcinoma. Their age ranged from 20 to 68 years with a median age of 32 years. The most common presentation was anterior midline painless neck swelling. The diagnosis was made on final histopathological examination post-operatively. Alignant change is rare complication of the most common congenital thyroid anomaly. This study highlights the occurrence of this disease in adults and provides data on manifestation and management of this rare disease.