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Aims: Onychomatricoma (OM), an uncommon benign fibroepithelial neoplasm of the nail unit, is sometimes diagnostically challenging for clinicians and pathologists. OM consistently expresses CD34, but no specific immunohistohemical markers or recurrent genetic alterations have been identified to date. Recent studies have suggested that Wnt signalling is a key molecular characteristic of OM. Methods and results: Ten cases were analysed: four classical OM including two with pleomorphic cells; two superficial acral fibromyxoma‐like variants of OM; three micropapilliferum variants of OM including one with pleomorphic cells; and one proliferating variant of OM. Immunohistochemically, the spindle cells were positive with CD34 (n = 10) and CD99 (n = 1), with focal reactivity for CD10 (n = 5). The epithelial component of the tumours expressed immunopositivity for LEF‐1. Using array comparative genomic hybridization (aCGH), we demonstrated that all OM, including its variants that were tested (n = 8), harboured a few copy number alterations with losses of whole or part of chromosome 13 including the RB1 gene (n = 8) and chromosome 16 (n = 6). Conclusion: We report a recurrent loss of RB1 (13q) as a possible driver molecular event in OM indicating a relationship between OM and other lesions of the spectrum of the so‐called '13q/RB1' family of tumours. We did not identify a role for the Wnt/beta‐catenin signalling pathway, as has been proposed in a recent study. LEF‐1 could be a potential sensitive and specific marker of OM and should be used in the differential diagnosis between OM, superficial acral fibromyxoma, and the CD34‐positive fibrosing family of tumours. [ABSTRACT FROM AUTHOR]

• We performed next-generation sequencing of 159 plasma samples from 69 patients with extensive-stage (ES)-SCLC. • Combination ctDNA and tissue testing improved the overall detection rate of actionable mutations from 19.4% to 26.9% compared with that of tissue detection alone. • ctDNA levels changed dynamically during the course of treatment and were significantly associated with decreased progression-free survival. Chemotherapy remains the mainstay of treatment for small-cell lung cancer (SCLC). Liquid biopsies provide a convenient and non-invasive detection method for monitoring disease progression in patients with SCLC. We performed next-generation sequencing of 159 plasma samples from 69 patients with extensive-stage (ES)-SCLC. Circulating tumor (ct)DNA levels were quantified in haploid genome equivalents per mL (hGE/mL). MuTect2 was used to detect single nucleotide variants and short insertions/deletions. The "enrichKEGG" function in the "clusterProfiler" R package was used to enrich the mutated genes that only appeared during disease progression. In our cohort, 66 of 69 (95.7%) plasma samples at the time of diagnosis had detectable somatic mutations; TP53 (89%) and RB1(56%) were the most frequent mutations, as well as copy number variations in some common SCLC-related genes such as RB1. Combination ctDNA and tissue testing improved the overall detection rate of actionable mutations from 19.4% to 26.9% compared with that of tissue detection alone. In addition, ctDNA levels changed dynamically during the course of treatment and were significantly associated with decreased progression-free survival. Notably, actionable mutations were detected at the time of diagnosis and during disease progression. Our study revealed a dynamic somatic mutation profile through continuous ctDNA detection and confirmed that ctDNA levels can reflect tumor burden and predict PFS in patients with extensive stage-SCLC. Furthermore, we demonstrated that plasma ctDNA assays can provide real-time information on somatic mutations for potential targeted therapies for SCLC. [ABSTRACT FROM AUTHOR]

Novel anti-EGFR therapies target resistance to standard-of-care anti-EGFR in patients with metastatic lung cancer. We describe tumors at progression versus at the initiation of novel anti-EGFR agents in patients with metastatic lung adenocarcinoma harboring EGFR mutation. This clinical case series reports the histological and genomic features and their evolution following disease progression under amivantamab or patritumab-deruxtecan in clinical trials. All patients had a biopsy at disease progression. Four patients harboring EGFR gene mutations were included. Three of them received anterior anti-EGFR treatment. Median delay to disease progression was 15 months (range: 4–24). At progression, all tumors presented a mutation in the TP53 signaling pathway associated with a loss of heterozygosis (LOH) of the allele in 75% (n = 3), and two tumors (50%) presented an RB1 mutation associated with LOH. Ki67 expression increased above 50% (range 50–90%) in all samples compared to baseline (range 10–30%), and one tumor expressed a positive neuroendocrine marker at progression. Our work reports the potential molecular mechanisms of resistance under novel anti-EGFR in patients with metastatic EGFR-mutated lung adenocarcinoma, with the transformation to a more aggressive histology with acquired TP53 mutation and/or the increase in Ki67 expression. These characteristics are usually found in aggressive Small Cell Lung Cancer. [ABSTRACT FROM AUTHOR]

Abstract Background Abnormalities in homologous recombination contribute to the aggressive nature of castration-resistant prostate cancer. Retinoblastoma transcriptional corepressor 1 (RB1) and breast cancer 2 (BRCA2) exist close to each other in the same chromosome, and the significance of their concurrent loss has become a hot topic in the field of cancer research. Case presentation A 61-year-old man presented with a chief complaint of a mass on his head and was diagnosed as multiple bone metastases from prostate cancer. He was treated with standard medication, but he died 2 years 6 months after being diagnosed with prostate cancer. Simultaneous biallelic loss of RB1 and BRCA2 as well as a truncating mutation of tumor protein p53 (TP53) were revealed by genomic analysis. Conclusion To our knowledge, this is the first report of castration-resistant prostate cancer (CRPC) with BRCA2 and RB1 co-loss and TP53 mutation. To establish a treatment strategy for highly malignant cases with such multiple genetic features is important.

The article titled "Onychomatricoma is not a subtype of superficial acral fibromyxoma: Can immunohistochemistry help in the differential diagnosis?" discusses the debate surrounding the classification of onychomatricoma (OM) and superficial acral fibromyxoma (SAFM) as distinct tumors. The authors argue that OM should be recognized as a fibrous neoplasm rather than a fibroepithelial neoplasm, based on their shared immunohistochemical profile and loss of RB1. However, the overall consensus is that OM and SAFM have clinical and histopathologic features that allow for easy differentiation. The article provides distinguishing features between the two tumors and acknowledges that the diagnosis of OM can be challenging in the absence of clinical information or when the nail plate is not submitted for examination. [Extracted from the article]

Gut microbiota are significantly associated with the occurrence and development of inflammatory bowel disease (IBD). Panax notoginseng saponins (PNS) could be used for colitis and to modulate gut microbiota. However, the mechanism behind the effects of PNS on anti-colitis that are pertinent to gut microbiota is largely unknown. This study aimed to evaluate the anti-colitis effects of PNS and explore the involved mechanism as it is related to gut microbiota. Results showed that PNS significantly alleviated dextran sulfate sodium (DSS)-induced colitis. Meanwhile, after PNS treatment, the tight junction proteins were enhanced and proinflammatory cytokines, such as TNF- α , IL-6, IL-1 β , and IL-17, were decreased. Furthermore, Bacteroides spp. were significantly increased after modeling, while PNS reduced their abundance and significantly increased the amount of Akkermansia spp. in vivo. Importantly, Akkermansia spp. and Bacteroides spp. were correlated with the IBD disease indicators. Moreover, fecal microbiota transplantation (FMT) experiments confirmed that PNS-reshaped gut microbiota significantly alleviated DSS-induced colitis, while A. muciniphila significantly reduced the levels of the LPS-induced cellular inflammatory factors IL-1 β and TNF- α. In conclusion, PNS alleviated colitis pertinent to the upregulation of Akkermania spp. and downregulation of Bacteroides spp. in the gut. [ABSTRACT FROM AUTHOR]

The root extract of Panax ginseng C.A. Meyer (Korean red ginseng/KRG extract) is a traditional Asian remedy introduced to dermal products for its antioxidative potential. However, little is known about technological aspects or skin penetration of main ginsenosides. Thus, stable oil-in-water nanoemulsions (NEs) and hydrogels for dermal delivery of KRG extract were developed and characterised using light scattering methods, analysis of flow properties and pH measurements. In addition, Rg1 and Rb1 contents were monitored by UHPLC/MS. Different surfactants (phosphatidylcholine, monoacylphosphatidylcholine and polysorbate 80) and polymers (polyacrylic acid and hydroxyethylcellulose) were tested and compared for their compatibility with KRG extract. The results showed that incorporation of KRG extract led to a significantly reduced formulation pH in hydroxyethylcellulose gels (−22%), NEs (−15%) and carbomer gels (−4–5%). The dynamic viscosity was in the range of 24–28 Pas at 10 s−1 for carbomer gels. The highest storage stability and skin permeation were observed for a hydroalcoholic gel with carbomer 50,000 and TRIS buffer (each of 1% w/w), containing ethanol (20% w/w) and KRG extract (2% w/w). Ex vivo diffusion cell studies confirmed skin permeation of the moderately lipophilic Rg1, but not the more hydrophilic Rb1 with a larger molecular weight. [ABSTRACT FROM AUTHOR]

High-grade (grade 3) neuroendocrine neoplasms (G3 NENs) have poor survival outcomes. From a clinical standpoint, G3 NENs are usually grouped regardless of primary site and treated similarly. Little is known regarding the underlying genomics of these rare tumors, especially when compared across different primary sites. We performed whole transcriptome (n = 46), whole exome (n = 40), and gene copy number (n = 43) sequencing on G3 NEN formalin-fixed, paraffin-embedded samples from diverse organs (in total, 17 were lung, 16 were gastroenteropancreatic, and 13 other). G3 NENs despite arising from diverse primary sites did not have gene expression profiles that were easily segregated by organ of origin. Across all G3 NENs, TP53, APC, RB1, and CDKN2A were significantly mutated. The CDK4/6 cell cycling pathway was mutated in 95% of cases, with upregulation of oncogenes within this pathway. G3 NENs had high tumor mutation burden (mean 7.09 mutations/MB), with 20% having >10 mutations/MB. Two somatic copy number alterations were significantly associated with worse prognosis across tissue types: focal deletion 22q13.31 (HR, 7.82; P = 0.034) and arm amplification 19q (HR, 4.82; P = 0.032). This study is among the most diverse genomic study of high-grade neuroendocrine neoplasms. We uncovered genomic features previously unrecognized for this rapidly fatal and rare cancer type that could have potential prognostic and therapeutic implications. [ABSTRACT FROM AUTHOR]

Aims: Pleomorphic xanthoastrocytoma (PXA) is a rare circumscribed glioma, characterized by frequent BRAF p. V600E mutation, and classified as grade 2 or 3. Owing to overlapping clinical–pathological features, the histological distinction from glioblastoma (GBM) with giant cells (GCs) is challenging. Based on the high frequency of TP53 and RB1 alterations in the latter, this study aimed to assess the value of BRAF, p53, and pRB immunostainings in the differential diagnosis. Methods and results: In 37 GBMs with ≥30% GCs and in eight PXAs, we assessed the alterations of 409 cancer-related genes and immunostainings for BRAF, p53, and pRB. GBMs with GCs were TP53- mutated in 30 cases, RB1-altered in 11, and BRAFmutated in none. PXAs were BRAF-mutated in six cases, TP53-mutated in three, and RB1-altered in none. pRb immunostaining was lost in 25 GBMs (11 RB1-altered and 14 RB1-unaltered), retained in all PXAs and six GBMs, and inconclusive in six GBMs. pRb loss had 100% specificity and 80.6% sensitivity for GBM with GCs. P53 immunostaining was observed in 22 TP53-mutated GBMs and in one TP53-mutated PXA. It showed 87.5% specificity and 60% sensitivity to identify GBM with GCs. BRAF immunostaining corresponded to BRAF mutation status and it had 100% specificity and 75% sensitivity for detecting PXA. Conclusion: This study shows for the first time that loss of pRB immunostaining is sensitive and specific for distinguishing GBM with GCs from PXA in routine practice. Thus, it could complement an immunohistochemical panel that includes BRAF and p53 immunostainings for the differential diagnosis. [ABSTRACT FROM AUTHOR]

Purpose: To identify the spectrum of RB1 gene mutations in 114 Chinese patients with retinoblastoma. Methods: Genomic DNA was extracted from the peripheral blood of 114 Rb patients. Polymerase chain reactions (PCRs) followed by direct Sanger sequencing were used to screen for mutations in the RB1 gene, which contains 26 exons with flanking intronic sequences, except exon 15. Clinical data, including gender, age at diagnosis, laterality of ocular lesions, and associated symptoms, were recorded and compared. Results: We identified five novel mutations in the RB1 gene. Twenty-five other mutations found in this study have been previously reported. A higher rate of RB1 mutations, with 47.3% of mutations among bilaterally affected patients vs. 6.8% within unilaterally affected patients, was also observed (p < 0.0001). Bilaterally affected patients were diagnosed earlier when compared to unilaterally affected patients (11 ± 7 months versus 20 ± 14 months, p = 0.0002). Furthermore, nonsense mutations were abundant (n = 14), followed by frameshift mutations (n = 8), splicing site mutations (n = 5), while missense mutations were few (n = 3). Conclusions: We found five novel mutations in RB1 genes, which expands the mutational spectrum of the gene. Children with bilateral Rb exhibited higher mutation rates and were diagnosed earlier than those with unilateral Rb. These findings will inform clinical diagnosis and genetic therapeutic targeting in Rb patients. [ABSTRACT FROM AUTHOR]

XPO1 is an attractive and promising therapeutic target frequently overexpressed in multiple hematological malignancies. The clinical use of XPO1 inhibitors in natural killer/T-cell lymphoma (NKTL) is not well documented. Here, we demonstrated that XPO1 overexpression is an indicator of poor prognosis in patients with NKTL. The compassionate use of the XPO1 inhibitor selinexor in combination with chemotherapy showed favorable clinical outcomes in three refractory/relapsed (R/R) NKTL patients. Selinexor induced complete tumor regression and prolonged survival in sensitive xenografts but not in resistant xenografts. Transcriptomic profiling analysis indicated that sensitivity to selinexor was correlated with deregulation of the cell cycle machinery, as selinexor significantly suppressed the expression of cell cycle-related genes. CDK4/6 inhibitors were identified as sensitizers that reversed selinexor resistance. Mechanistically, targeting CDK4/6 could enhance the anti-tumor efficacy of selinexor via the suppression of CDK4/6-pRb-E2F-c-Myc pathway in resistant cells, while selinexor alone could dramatically block this pathway in sensitive cells. Overall, our study provids a preclinical proof-of-concept for the use of selinexor alone or in combination with CDK4/6 inhibitors as a novel therapeutic strategy for patients with R/R NKTL. • XPO1 is overexpressed in NKTL and correlates with a poor prognosis. • XPO1 inhibitor selinexor combined with chemotherapy showed favorable outcomes in R/R NKTL patients. • Dysregulation of CDK4/6-pRb-E2F-c-Myc axis is associated with resistance to selinexor in NKTL. • Concurrent targeting of CDK4/6 and XPO1 may provide a potential therapeutic strategy for patients with R/R NKTL. [ABSTRACT FROM AUTHOR]

Retinoblastoma is the most common eye cancer in children. It is caused by pathogenic alterations of both alleles of the tumor suppressor gene RB1. In heritable retinoblastoma, a constitutional RB1 variant predisposes the cells to tumor formation, and loss of the other allele is a prerequisite for the development of retinoblastoma. Heritable retinoblastoma is inherited in an autosomal dominant manner; however, the majority of cases are the result of a de novo pathogenic RB1 variant. Penetrance is usually high (>90%), but with marked inter-familial variability. In some families, penetrance is incomplete and family members who develop tumors tend to remain unilaterally affected. Moreover, some families with low penetrance also show a parent-of-origin effect. We describe a patient with unilateral retinoblastoma caused by a previously unreported likely pathogenic RB1 variant (c.1199T>C) that disrupts a highly conserved amino acid residue within the A-box functional domain. Segregation analysis showed that the variant had unusually low penetrance as nine non-affected family members carried the same variant. We emphasize the use of genetic analysis on tumor DNA for classifying the RB1 variant, and underline the challenges in clinical management and counseling of families carrying the specific RB1 variant. [ABSTRACT FROM AUTHOR]

Lipoleiomyomas are rare variants of uterine leiomyomas rarely studied in the literature. We retrospectively studied 20 cases of uterine lipoleiomyomas showing that these lesions represent 0.7 % of all uterine leiomyomas diagnosed histologically. The patients did not experience any recurrence, and the tumors showed no morphological criteria of malignancy. They did not show significant p16, p53 or MiB1 expression. They showed diffuse and strong expression or estrogen and progesterone receptors by the smooth muscle component but without accompanying expression by the adipocytic component in one third of the cases. Androgen receptors were rarely expressed. They expressed in their majority HMGA2 in both components, while RB1 was usually not found. Fumarate hydratase (FH) is expressed by lipoleiomyomas, while they are negative for HMB45. In conclusion, uterine lipoleiomyomas are rare, benign tumors, characterized by HMGA2 expression, while they show no elements suspicious of malignancy, PEComas or FH deficiency. The role of RB1 in these tumors should be further explored. [ABSTRACT FROM AUTHOR]

Background: Abnormalities of myelin, which increases the efficiency of action potential conduction, are found in neurological disorders. Korean Red Ginseng (KRG) demonstrates therapeutic efficacy against some of these conditions, however effects on oligodendrocyte (OL)s are not well known. Here, we examined the effects of KRG-derived components on development and protection of OL-lineage cells. Methods: Primary OL precursor cell (OPC) cultures were prepared from neonatal mouse cortex. The protective efficacies of the KRG components were examined against inhibitors of mitochondrial respiratory chain activity. For in vivo function of Rb1 on myelination, after 10 days of oral gavage into adult male mice, forebrains were collected. OPC proliferation were assessed by BrdU incorporation, and differentiation and myelination were examined by qPCR, western blot and immunocytochemistry. Results: The non-saponin promoted OPC proliferation, while the saponin promoted differentiation. Both processes were mediated by AKT and extracellular regulated kinase (ERK) signaling. KRG extract, the saponin and non-saponin protected OPCs against oxidative stress, and both KRG extract and the saponin significantly increased the expression of the antioxidant enzyme. Among 11 major ginsenosides tested, Rb1 significantly increased OL membrane size in vitro. Moreover, Rb1 significantly increased myelin formation in adult mouse brain. Conclusion: All KRG components prevented OPC deaths under oxidative stress. While non-saponin promoted proliferation, saponin fraction increased differentiation and OL membrane size. Furthermore, among all the tested ginsenosides, Rb1 showed the biggest increase in the membrane size and significantly enhanced myelination in vivo. These results imply therapeutic potentials of KRG and Rb1 for myelin-related disorders.

This study aimed to assess the anti-proliferative capabilities of the three probiotic strains on breast cancer (MCF7) and test their anticancer capabilities on RP1 and RASSF1A Genes. Three probiotics bacterial strains: Lactobacillus casei ss. casei (LC 1093), Lactobacillus delbreuckii ss. bulgaricus LD (1102) and Bifidobacterium bifidum (BB 1334) were tested for their anti-proliferative capabilities on cell lines via trypan blue test and MTT assay. Their anti-methylation activities were tested using methylation-specific PCR (MSP). Results revealed that Lactobacillus casei strain achieved the highest percentage of cancer cell death. The effects of these strains on the methylation status of RASSF1A and RB1 promotor regions in breast cancer cells were tested. The unmethylation-specific primers of both genes were able to generate a defined band. The methylation patterns were reshaped when compared to the untreated MCF7 cell line showing the epigenetic delaying mechanism of the probiotic cell free filtrate by interfering the methylation mechanism of breast cancer on two tested genes.

High‐grade neuroendocrine carcinoma of gynecologic origin (NEC‐GYN) is a highly aggressive cancer that often affects young women. The clinical management of NEC‐GYN is typically extrapolated from its counterpart, small cell carcinoma of the lung (SCLC), but, unfortunately, available therapies have limited benefit. In our NEC‐GYN cohort, median progression‐free survival (PFS) and overall survival (OS) were 1 and 12 months, respectively, indicating the highly lethal nature of this cancer. Our comprehensive genomic analyses unveiled that NEC‐GYN harbors a higher mutational burden with distinct mutational landscapes from SCLC. We identified 14 cancer driver genes, including the most frequently altered KMT2C (100%), KNL1 (100%), NCOR2 (100%), and CCDC6 (93%) genes. Transcriptomic analysis identified several novel gene fusions; astonishingly, the MALAT1 lincRNA gene was found in ˜ 20% of all fusion events in NEC‐GYN. Furthermore, NEC‐GYN exhibited a highly immunosuppressive state, intact RB1 expression, and was uniquely enriched with the YAP1high molecular subtype. Our study identifies several potential therapeutic targets and suggests an urgent need to re‐evaluate the treatment options for NEC‐GYN.

Abstract Giant cell glioblastoma (GC-GBM) is a rare variant of IDH-wt GBM histologically characterized by the presence of numerous multinucleated giant cells and molecularly considered a hybrid between IDH-wt and IDH-mutant GBM. The lack of an objective definition, specifying the percentage of giant cells required for this diagnosis, may account for the absence of a definite molecular profile of this variant. This study aimed to clarify the molecular landscape of GC-GBM, exploring the mutations and copy number variations of 458 cancer-related genes, tumor mutational burden (TMB), and microsatellite instability (MSI) in 39 GBMs dichotomized into having 30–49% (15 cases) or ≥ 50% (24 cases) GCs. The type and prevalence of the genetic alterations in this series was not associated with the GCs content ( 10 mut/Mb, including two (5%) that harbored MSI and one with a POLE mutation. The frequency of RB1 and NF1 alterations and TMB counts were significantly higher compared to 567 IDH wild type (P

Objective: Bone is a highly dynamic organ that undergoes constant bone formation and remodeling, and glucose as a major nutrient is necessary for bone formation and remodeling. Retinoblastoma (Rb1) is a critical regulator of mesenchymal stem cells (MSCs) fate, but how Rb1 regulates bone formation and remodeling is poorly understood. Methods: We generated MSCs- and osteoprogenitors-specific Rb1 knockout mouse models and utilized these models to explore the function and mechanism of Rb1 in regulating bone formation and remodeling in vivo and in vitro primary cell culture. Results: Rb1 deficiency in MSCs significantly increased bone mass and impaired osteoclastogenesis. Consistently, depletion of Rb1 in osteoprogenitors significantly promoted bone formation. Mechanistically, loss of Rb1 in MSCs elevated YAP nuclear translocation and transcriptional activity of YAP/TEAD1 complex, thereby increasing the transcriptional expression of Glut1 and OPG. Moreover Prx1-Cre; Rb1f/f mice displayed hypoglycemia with increased systemic glucose tolerance instead of increased insulin level. In vitro data revealed that Rb1-mutant MSCs enhanced glucose uptake and lactate and ATP production. Increased osteogenesis caused by increased glucose metabolism and decreased osteoclastogenesis caused by increased expression of OPG eventually resulted in increased bone formation and remodeling. Conclusions: Collectively, these findings demonstrated that Rb1 in MSCs inhibits YAP-medicated Glut1 and OPG expression to control glucose metabolism, osteogenesis and osteoclastogenesis during bone formation and remodeling, which provide new insights that controlling Rb1 signaling may be a potential strategy for osteopetrosis.

Neuroendocrine carcinomas (NEC) are aggressive malignant diseases. Etoposide-based rechallenge (EBR) and the prognostic role of RB transcriptional corepressor 1 (RB1) status in second-line chemotherapy (2L) have not been studied. The objectives of this study were to report the results of 2L including EBR as well as prognostic factors in a national retrospective multicentre study. NEC patients treated with 2L and further, with tissue samples available, were included. RB1 status and morphological classification were reviewed centrally. Among the 121 NEC patients (40% female, median age 61 years) included, there were 73 small-cell NEC (60%), 34 large-cell NEC (28%) and 14 NEC (not otherwise specified, 12%). Primary sites were lung (39%), gastroenteropancreatic (36%), other (13%) and unknown (12%). Median Ki-67 index was 80%. Median progression-free survival (PFS) and overall survival (OS) under 2L were 2.1 and 6.2 months, respectively. No difference was observed between patients who received an 'adenocarcinoma-like' or a 'neuroendocrine-like' 2L or according to the RB1 status. T horacic NEC primary was the only adverse prognostic factor for OS. EBR, administered to 31 patients, resulted in a 62% disease control rate with a median PFS and OS of 3.2 and 11.7 months, respectively. In the 94 patients with a relapse-free interval of ≥3 months after first-line platinum--etoposide chemotherapy, the median OS was 12 months in patients who received EBR as compared to 5.9 months in patients who did not (P = 0.043). EBR could be the best 2L option for patient with initial response to first-line platinum--etoposide lasting at least 3 months. RB1 status does not provide prognostic information in this setting. [ABSTRACT FROM AUTHOR]

This study aimed to identify differences in genetic alterations between low- and high-grade lesions in myxofibrosarcoma (MFS) and to examine the efficacy of immune checkpoint inhibitors in 45 patients with MFS. First, genetic differences between low- and high-grade components within the same tumor were analyzed in 11 cases using next-generation sequencing. Based on the obtained data, Sanger sequencing was performed for TP53 mutations in the remaining 34 patients. Loss of heterozygosity (LOH) analysis was performed at the TP53 and RB1 loci. Immunohistochemistry was performed for FGFR3, KIT, MET, programmed death receptor ligand 1 (PD-L1), CD8, FOXP3, and mismatch repair proteins. The microsatellite instability status was also evaluated in all cases. TP53 deleterious mutations and LOH at TP53 and RB1 loci were detected significantly more frequently in high-grade than in low-grade MFS (P = 0.0423, 0.0455, and 0.0455, respectively). LOH at the RB1 locus was significantly associated with shorter recurrence-free survival in both univariate and multivariate analyses. TP53 alterations, such as mutation and LOH, were more frequently observed in low-grade areas within high-grade MFS than in pure low-grade MFS. The positive PD-L1 expression rate was 35.6% (16/45), and all these 16 cases were high-grade. A high density of both CD8+ and FOXP3+ tumor-infiltrating lymphocytes was associated with PD-L1 positivity. LOH at the RB1 locus was identified an independent adverse prognostic factor for recurrence-free survival in patients with MFS. Immune checkpoint inhibitors may be a therapeutic option for a subset of high-grade MFS. [ABSTRACT FROM AUTHOR]

Simple Summary: Cancers are caused by genetic alterations called mutations. In some cases, specific mutation combinations act synergistically to provide unique advantages for cancer development. These mutation combinations are observed more frequently than by random chance. In this study, we investigated a large public tumor mutation database and found the most diverse and frequent concurrent mutations occur in TP53 and RB1. We enumerated the cancer types with TP53/RB1 co-mutations and investigated the patient outcome and the specific characteristics of cancer cells with TP53/RB1 co-mutations, especially the drugs that can and cannot be used to kill these cells. Our work provides a tool for cancer researchers to investigate co-mutations and provides insights into the treatment of TP53/RB1 co-mutated cancers. Nearly all tumors have multiple mutations in cancer-causing genes. Which of these mutations act in tandem with other mutations to drive malignancy and also provide therapeutic vulnerability? To address this fundamental question, we conducted a pan-cancer screen of co-mutation enrichment (looking for two genes mutated together in the same tumor at a statistically significant rate) using the AACR-GENIE 11.0 data (AACR, Philadelphia, PA, USA). We developed a web tool for users to review results and perform ad hoc analyses. From our screen, we identified a number of such co-mutations and their associated lineages. Here, we focus on the RB1/TP53 co-mutation, which we discovered was the most frequently observed co-mutation across diverse cancer types, with particular enrichment in small cell carcinomas, neuroendocrine carcinomas, and sarcomas. Furthermore, in many cancers with a substantial fraction of co-mutant tumors, the presence of concurrent RB1/TP53 mutations is associated with poor clinical outcomes. From pan-cancer cell line multi-omics and functional screening datasets, we identified many targetable co-mutant-specific molecular alterations. Overall, our analyses revealed the prevalence, cancer type-specificity, clinical significance, and therapeutic vulnerabilities of the RB1/TP53 co-mutation in the pan-cancer landscape and provide a roadmap forward for future clinical translational research. [ABSTRACT FROM AUTHOR]

Esophageal basaloid squamous cell carcinoma (EBSCC) is a poorly differentiated variant of esophageal squamous cell carcinoma (ESCC). We aimed to investigate the clinicopathological and molecular biological characteristics of EBSCC and enrolled 58 patients with EBSCCs. Clinicopathological factors including age, sex, tumor size and location, gross tumor type (superficial, protrusive, ulcerative, and unclassifiable), lymphovascular invasion, infiltrative growth, intramural invasion, TNM stage, and dominant histological type were examined. EBSCCs were classified into four types (solid, cribri, microcystic, and tubular) according to the dominant histology. Next-generation sequencing (NGS) of a cancer hotspot panel was performed in 19 cases. NGS identified TP53 as the most frequently mutated gene, and copy number variation analysis revealed the most frequent loss of heterozygosity (LOH) at the ataxia telangiectasia mutated (ATM) and retinoblastoma 1 (RB1) loci. Target sequencing for TP53 was performed for the remaining 39 cases. We also performed LOH analysis for TP53, ATM, and RB1 and immunohistochemical staining for p53, ATM, and Rb in all cases. The rates of TP53 mutations and LOH and p53 aberrant expression were high (79.3%, 63.2%, and 72.4%, respectively); however, the frequencies were similar to those reported for ESCC. LOH rates of the RB1 and ATM loci were also high (55.3% and 67.2%, respectively). Overall survival rate was 66.5%, and recurrence-free survival rate was 55.0%. Only conventional clinicopathological factors had a prognostic impact in EBSCC; the microcystic type had the poorest prognosis. Our findings could be useful in developing novel treatment strategies for EBSCC. [ABSTRACT FROM AUTHOR]

Aims: Large‐cell neuroendocrine carcinoma (LCNEC) and small‐cell carcinoma (SCLC) of lung encompass high‐grade neuroendocrine tumour category and share several fundamental features. As both tumours may respond to different treatment modalities and show unique molecular alterations distinction between the two is clinically relevant, but can be challenging due to sampling and fixation issues and shared morphological features. Methods: Surgically resected primary SCLC (n = 129) and LCNEC (n = 27) were immunohistochemically stained with Rb1, cyclin D1 and p16 using tissue microarray (TMA), and expression patterns of the proteins were compared between the two to identify the discriminatory pattern. Results: All markers had high diagnostic accuracy; Rb1 was the highest followed by p16 and cyclin D1. The majority of SCLC had the pattern Rb1−/p16+/cyclin D1– and more than half of LCNEC had Rb1+/p16−/cyclin D1+. Overall, the expression pattern Rb1– and cyclin D1– was strongly associated with the diagnosis of SCLC, while the pattern Rb1+ and/or cyclin D1+ was strongly associated with LCNEC. The use of this simplified expression pattern leads to a diagnostic accuracy of 97.3%. p16 did not add to further discrimination. The heterogeneity in Rb1, cyclin D1 and p16 expression was insignificant in SCLCs compared with LCNECs. Conclusions: Use of Rb1, cyclin D1 and p16 immunohistochemistry can distinguish the two with high accuracy. Notably, the Rb1−/cyclin D1– pattern in given tumour sample would confirm the diagnosis of SCLC. Our results could be extrapolated and applied to routine diagnostic samples such as biopsies and cytology samples. [ABSTRACT FROM AUTHOR]

A mosaic state arises when pathogenic variants are acquired in certain cell lineages during postzygotic development, and mosaic individuals may present with a generalized or localized phenotype. Here, we review the current state of knowledge regarding mosaicism for eight common tumor suppressor genes—NF1, NF2, TSC1, TSC2, PTEN, VHL, RB1, and TP53—and their related genetic syndromes/entities. We compare and discuss approaches for comprehensive diagnostic genetic testing, the spectrum of variant allele frequency, and disease severity. We also review affected individuals who have no mutation identified after conventional genetic analysis, as well as genotype–phenotype correlations and transmission risk for each tumor suppressor gene in full heterozygous and mosaic patients. This review provides new insight into similarities as well as marked differences regarding the appreciation of mosaicism in these tumor suppressor syndromes. [ABSTRACT FROM AUTHOR]

Background: Regulatory T (Treg) cells are important components of the tumour microenvironment (TME) that play roles in gastric cancer (GC) metastasis. Although tumour cells that undergo epithelial‐mesenchymal transition (EMT) regulate Treg cell function, their regulatory mechanism in GC remains unclear. Methods: The miR‐192‐5p was identified by examining three Gene Expression Omnibus GC miRNA expression datasets. RNA immunoprecipitation (RIP) and dual‐luciferase reporter assays were conducted to identify interactions between miR‐192‐5p and RB1. The role of miR‐192‐5p/RB1 in GC progression was evaluated based on EdU incorporation, wound healing and Transwell assays. An in vitro co‐culture assay was performed to measure the effect of miR‐192‐5p/RB1 on Treg cell differentiation. In vivo experiments were conducted to explore the role of miR‐192‐5p in GC progression and Treg cell differentiation. Results: MiR‐192‐5p was overexpressed in tumour and was associated with poor prognosis in GC. MiR‐192‐5p bound to the RB1 3′‐untranslated region, resulting in GC EMT, proliferation, migration and invasion. MiR‐192‐5p/RB1 mediated interleukin‐10 (IL‐10) secretion by regulating nuclear factor‐kappaBp65 (NF‐κBp65), affecting Treg cell differentiation. NF‐κBp65, in turn, promoted miR‐192‐5p expression and formed a positive feedback loop. Furthermore, in vivo experiments confirmed that miR‐192‐5p/RB1 promotes GC growth and Treg cell differentiation. Conclusion: Collectively, our studies indicate that miR‐192‐5p/RB1 promotes EMT of tumour cells, and the miR‐192‐5p/RB1/NF‐κBp65 signaling axis induces Treg cell differentiation by regulating IL‐10 secretion in GC. Our results suggest that targeting miR‐192‐5p/RB1/NF‐κBp65 /IL‐10 may pave the way for the development of new immune treatments for GC. [ABSTRACT FROM AUTHOR]

Purpose: Neuroendocrine carcinomas (NECs) of the stomach are extremely rare, but fatal. However, our understanding of the genetic alterations in gastric NECs is limited. We aimed to evaluate genomic and clinicopathological characteristics of gastric NECs and mixed adenoneuroendocrine carcinomas (MANECs)., Materials and Methods: Fourteen gastric NECs, 3 gastric MANECs, and 1381 gastric adenocarcinomas were retrieved from the departmental next-generation sequencing database between 2017 and 2019. Clinicopathological parameters and next-generation sequencing test results were retrospectively collected and reviewed., Results: Gastric NECs and MANECs frequently harbored alterations of TP53, RB1, SMARCA4, RICTOR, APC, TOP1, SLX4, EGFR, BRCA2, and TERT. In contrast, gastric adenocarcinomas exhibited alterations of TP53, CDH1, LRP1B, ARID1A, ERBB2, GNAS, CCNE1, NOTCH, and MYC. Mutations of AKT3, RB1, and SLX4; amplification of BRCA2 and RICTOR; and deletion of ADAMTS18, DDX11, KLRC3, KRAS, MAX, NFKBIA, NUDT7, and RB1 were significantly more frequent in gastric NECs and MANECs than in gastric adenocarcinomas. The presence of LRP1B mutation was significantly associated with longer overall survival (OS), whereas RB1 mutation and advanced TNM stage were associated with shorter OS., Conclusion: We identified frequently mutated genes and potential predictors of survival in patients with gastric NECs and MANECs.

Retinoblastoma is the most common intraocular tumor in children and is caused by biallelic inactivation of the RB1 gene. The identification of RB1 germline variants in patients with retinoblastoma and their families is critical for early diagnosis and prevention. In this study, genetic testing was conducted on the genomic DNA of 203 patients with retinoblastoma using a combined approach of direct sequencing and multiplex ligation-dependent probe amplification (MLPA) assays for genotype-phenotype correlation studies. Sixty-five germline variants were identified in 80 of the 203 patients, with 67 bilateral and 13 unilateral retinoblastoma cases. The variant detection rates in the bilateral and unilateral cases were 88% and 10%, respectively. Eighteen novel variants were identified. Variants were classified according to their presence, mutation pattern, location, molecular consequences, and pathogenicity. Subsequently, the genotypes and phenotypes of the 203 patients were evaluated. Variants were associated with age at diagnosis (p < 0.001), laterality (p < 0.001), and tumor size (p = 0.010). The molecular consequences of the variants were related to laterality (p < 0.001) and tumor size (p = 0.001). The pathogenicity of the variants was associated with age at diagnosis (p = 0.001), laterality (p = 0.0212), treatment response (p = 0.0470), and tumor size (p = 0.002). These results suggest that patient phenotypes are associated with the inherent characteristics of germline RB1 variants. These findings indicate the potential application of genetic testing results in clinical practice., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: The diagnosis of treatment-related neuroendocrine prostate cancer (t-NEPC) often involves a pathological assessment and immunohistochemistry (IHC) for neuroendocrine markers. Genomic alterations in RB1 and TP53 are frequently observed in NEPC and are believed to play a crucial role in the transformation of adenocarcinoma to NEPC. In this study, we examined the clinicopathologic, immunohistochemical, and genetic features of patients with t-NEPC to better understand their prognosis and diagnostic utility., Methods: This retrospective study reviewed the records of patients diagnosed with t-NEPC at Kobe University Hospital between October 2018 and December 2022. Clinical data, including age, serum neuroendocrine marker levels, and treatment history, were collected. IHC was performed for conventional neuroendocrine markers (synaptophysin, chromogranin A, and CD56) and RB1 and p53 expression. Next-generation sequencing (NGS) was conducted using FoundationOne® CDx to identify mutations in RB1 and TP53., Results: This study included 20 patients with t-NEPC. The median time from ADT initiation to development was 42.8 months. IHC revealed RB1 loss in 75% of cases and p53 abnormalities in 75% of cases. NGS identified RB1 mutations in 55% and TP53 mutations in 75% of cases. The concordance between NGS and IHC results was high, with 70% (14/20) agreement for RB1/RB1 and 80% (16/20) for p53/TP53. The immunostaining and genomic analysis of RB1/RB1 and p53/TP53 showed abnormal findings for the four negative cases for conventional neuroendocrine markers., Conclusions: This study indicated high concordance between IHC and NGS findings for RB1/RB1 and p53/TP53 in t-NEPC. We provide a comprehensive benchmark of NGS performance compared with IHC, and these findings may help increase the diagnostic sensitivity of t-NEPC., (© 2024 Wiley Periodicals LLC.)

Aging brings about physiological dysfunction, disease, and eventual mortality. An increasing number of studies indicate that aging can easily lead to dysbiosis of the gut microbiota, which can further affect digestion, nerves, cognition, emotions, and more. Therefore, gut bacteria play an important role in regulating the physical functions of aging populations. While saponins, the primary components of American ginseng , are frequently utilized for treating common ailments in the elderly due to their potent antioxidant properties, there is a scarcity of comprehensive studies on aging organisms. This study focused on 18 month old aging mice and investigated the effects of single intervention and combined intervention of R b1 and R e , the main components of Panax quinquefolium saponins, on the gut microbiota of aging mice. High throughput 16s RNA gene sequencing analysis was performed on the gut contents of the tested mice, and the results showed that R b1 and R e had a significant impact on the gut microbiota. R b1 , R e , and R b1  + R e can effectively enhance the diversity of gut microbiota, especially in the combined Rb1 + Re group, which can recover to the level of young mice. Re can promote the abundance of probiotics such as Lactobacillus, Lactobacillaceae, and Lactobacillus, and inhibit the abundance of harmful bacteria such as Enterobacteriaceae. This indicates that the intervention of R b1 , R e , and R b1  + R e can maintain the homeostasis of gut microbiota, and the combined application of R b1  + R e has a better effect. The relationship between aging, brain gut axis, and gut microbiota is very close. Saponins can improve the gut microbiota of aging individuals by maintaining the balance of gut microbiota and the normal function of the brain gut axis, enabling the body to achieve a gut microbiota homeostasis closer to that of young healthy mice., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Shi, Fan, Liu and Zhang.)

The hindbrain, which develops from the anterior end of the neural tube expansion, can differentiate into the metencephalon and myelencephalon, with varying sizes and functions. The midbrain-hindbrain boundary (MHB) and hindbrain myelencephalon/ventral midline (HMVM) are known to be the source of the progenitors for the anterior hindbrain and myelencephalon, respectively. However, the molecular networks regulating hindbrain morphogenesis in these structures remain unclear. In this study, we show that retinoblastoma 1 (rb1) is highly expressed at the MHB and HMVM in zebrafish. Knocking out rb1 in mice and zebrafish results in an enlarged hindbrain due to hindbrain neuronal hyperproliferation. Further study reveals that Rb1 controls the hindbrain morphogenesis by suppressing the expression of Gbx1/Gbx2, essential transcription factors for hindbrain development, through its binding to E2f3/Hdac1, respectively. Interestingly, we find that Gbx1 and Gbx2 are expressed in different types of hindbrain neurons, suggesting distinct roles in hindbrain morphogenesis. In summary, our study clarifies the specific role of RB1 in hindbrain neural cell proliferation and morphogenesis by regulating the E2f3-Gbx1 axis and the Hdac1-Gbx2 axis. These findings provide a research paradigm for exploring the differential proliferation of neurons in various brain regions., Competing Interests: Conflict of interest The authors declare no conflict of interest., (Copyright © 2024 Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, and Genetics Society of China. Published by Elsevier Ltd. All rights reserved.)

Prostate cancer is the second most common malignancy among men in the world, posing a serious threat to men's health and lives. RB1 is the first human tumor suppressor gene to be described, and it is closely associated with the development, progression, and suppression of a variety of tumors. It was found that the loss of RB1 is an early event in prostate cancer development and is closely related to prostate cancer development, progression and treatment resistance. This paper reviews the current status of research on the relationship between RB1 and prostate cancer from three aspects: RB1 and prostate cell lineage plasticity; biological behavior; and therapeutic resistance. Providing a novel perspective for developing new therapeutic strategies for RB1-loss prostate cancer., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Genetic alterations in the retinoblastoma susceptibility gene (RB1) are present in up to 40% of triple-negative breast cancers (BCs) and frequent in tumors with neuroendocrine differentiation, including small cell neuroendocrine carcinoma. Data on RB1 genetic alterations in estrogen receptor (ER)-positive BCs are scarce. In this study, we sought to define the morphologic, immunohistochemical, and genetic features of ER-positive BCs harboring somatic alterations in RB1, with emphasis on neuroendocrine differentiation. ER-positive BCs with pathogenic RB1 genetic alterations were identified in <1% of cases (N = 55) from a cohort of 6026 BCs previously subjected to targeted next-generation sequencing, including 23 primary BCs (pBCs) and 32 recurrent/metastatic BCs (mBCs). In cases where loss of heterozygosity of the wild-type RB1 allele could be assessed (93%, 51/55), most pBCs (82%, 18/22) and mBCs (90%, 26/29) exhibited biallelic RB1 inactivation, primarily through loss-of-function mutation and loss of heterozygosity (98%, 43/44). Upon histologic review, a subset of RB1-altered tumors exhibited neuroendocrine morphology (13%, 7/55), which correlated with expression of neuroendocrine markers (39%, 9/23) in both pBCs (27%, 3/11) and mBCs (50%, 6/12). Loss of Rb protein expression was observed in BCs with biallelic RB1 loss only, with similar frequency in pBCs (82%, 9/11) and mBCs (75%, 9/12). All cases with neuroendocrine marker expression (n = 9) and/or neuroendocrine morphology (n = 7) harbored biallelic genetic inactivation of RB1 and exhibited Rb loss of expression. TP53 (53%, 29/55) and PIK3CA (45%, 25/55) were the most frequently comutated genes across the cohort. Overall, these findings suggest that ER-positive BCs with biallelic RB1 genetic alterations frequently exhibit Rb protein loss, which correlates with neuroendocrine differentiation in select BCs. This study provides insights into the molecular and phenotypic heterogeneity of BCs with RB1 genetic inactivation, underscoring the need for further research into the potential clinical implications associated with these tumors., (Copyright © 2024 United States & Canadian Academy of Pathology. Published by Elsevier Inc. All rights reserved.)

DNA hypermethylation events occur frequently in human cancers, but less is known of the mechanisms leading to their initiation. Retinoblastoma, an intraocular cancer affecting young children, involves bi-allelic inactivation of the RB1 gene (RB−/-). RB1 encodes a tumour suppressing, cell cycle regulating transcription factor (pRB) that binds and regulates the RB1 core and other E2F responsive promoters with epigenetic functions that include recruitment of histone deacetylases (HDACs). Evidence suggests that bi-allelic epigenetic inactivation/hypermethylation of the RB1 core promoter (PrE-/E-), is specific to sporadic retinoblastomas (frequency~10%), whereas heritable RB1 promoter variants (Pr−/+, frequency~1-2%) are not associated with known epigenetic phenomena. We report heritable Pr−/- retinoblastomas with the expected loss of pRB expression, in which hypermethylation consistent with distal boundary displacement (BD) relative to normal peripheral blood DNAs was detected in 4/4 cases. In contrast, proximal BD was identified in 16/16 RB−/- retinoblastomas while multiple boundaries distal of the core promoter was further identified in PrE-/E-and PrE-/E+ retinoblastomas. However, weak or no DNA hypermethylation/BD in peripheral blood DNA was detected in 8/9 Pr−/+ patients, with the exception, a carrier of a microdeletion encompassing several RB1 promoter elements. These findings suggest that loss of boundary control may be a critical step leading to epigenetic inactivation of the RB1 gene and that novel DNA methylation boundaries/profiles identified in the RB1 promoter of Pr−/- retinoblastomas, may be the result of epigenetic phenomena associated with epimutation in conjunction with loss of pRB expression/binding and/or RB1 promoter interactions with boundary control elements.

Purpose: Retinoblastomas are malignant eye tumors diagnosed in young children. Most retinoblastomas are genetically characterized by biallelic inactivation of the RB1 gene. However, 1.5% of tumors demonstrate high-level amplification of the proto-oncogene MYCN. Patients with MYCN-amplified RB1-proficient retinoblastoma receive a diagnosis at an earlier age and show a clinically and histologically more malignant phenotype. This study aimed to identify genome-wide molecular features that distinguish this subtype from other retinoblastomas. Design: Cohort study. Participants: Forty-seven retinoblastoma tumors, comprising 36 RB1–/–, 4 RB1+/–, and 7 RB1+/+ tumors. In total, 5 retinoblastomas displayed high-level MYCN amplification, with 3 being RB1+/+, 1 being RB1+/–, and 1 being RB1–/–. Methods: Integrated analysis, based on gene expression, methylation, and methylation-expression correlations, was performed to identify distinct molecular components of MYCN-amplified RB1-proficient retinoblastomas compared with other retinoblastoma subtypes. The methylation and methylation-expression correlation analysis was initially conducted within a subset of samples (n = 15) for which methylation profiles were available. The significant findings were cross-validated in the entire cohort (n = 47) and in publicly available data. Main Outcome Measures: Differentially expressed genes/pathways, differentially methylated genes, and methylation-driven differential gene expression. Results: A large number of genes (n = 3155) were identified with distinct expression patterns in MYCN-amplified RB1-proficient retinoblastomas. The upregulated and downregulated genes were associated with translation and cell-cycle processes, respectively. Methylation analysis revealed distinct methylated patterns in MYCN-amplified RB1-proficient tumors, many of which showing significant impact on gene expression. Data integration identified a 40-gene expression signature with hypermethylated state resulting in a significant downregulation in MYCN-amplified RB1-proficient retinoblastomas. Cross-validation using the entire cohort and the public domain expression data verified the overall lower expression of these genes not only in retinoblastomas with a MYCN-amplified RB1-proficient background, but also in MYCN-amplified neuroblastomas. These include the metabolism-associated TSTD1 gene and the cyclin-dependent kinase inhibitor gene CDKN2C. Conclusions: MYCN-amplified RB1-proficient retinoblastomas display significantly distinct molecular features compared with other retinoblastomas, including a set of 40 hypermethylation-driven downregulated genes. This gene set can give insight into the biology of MYCN-amplified retinoblastomas and may help us to understand the more aggressive clinical behavior.

Abstract Background Regulatory T (Treg) cells are important components of the tumour microenvironment (TME) that play roles in gastric cancer (GC) metastasis. Although tumour cells that undergo epithelial‐mesenchymal transition (EMT) regulate Treg cell function, their regulatory mechanism in GC remains unclear. Methods The miR‐192‐5p was identified by examining three Gene Expression Omnibus GC miRNA expression datasets. RNA immunoprecipitation (RIP) and dual‐luciferase reporter assays were conducted to identify interactions between miR‐192‐5p and RB1. The role of miR‐192‐5p/RB1 in GC progression was evaluated based on EdU incorporation, wound healing and Transwell assays. An in vitro co‐culture assay was performed to measure the effect of miR‐192‐5p/RB1 on Treg cell differentiation. In vivo experiments were conducted to explore the role of miR‐192‐5p in GC progression and Treg cell differentiation. Results MiR‐192‐5p was overexpressed in tumour and was associated with poor prognosis in GC. MiR‐192‐5p bound to the RB1 3′‐untranslated region, resulting in GC EMT, proliferation, migration and invasion. MiR‐192‐5p/RB1 mediated interleukin‐10 (IL‐10) secretion by regulating nuclear factor‐kappaBp65 (NF‐κBp65), affecting Treg cell differentiation. NF‐κBp65, in turn, promoted miR‐192‐5p expression and formed a positive feedback loop. Furthermore, in vivo experiments confirmed that miR‐192‐5p/RB1 promotes GC growth and Treg cell differentiation. Conclusion Collectively, our studies indicate that miR‐192‐5p/RB1 promotes EMT of tumour cells, and the miR‐192‐5p/RB1/NF‐κBp65 signaling axis induces Treg cell differentiation by regulating IL‐10 secretion in GC. Our results suggest that targeting miR‐192‐5p/RB1/NF‐κBp65 /IL‐10 may pave the way for the development of new immune treatments for GC.

Osteosarcoma (OS) is the most prevalent type of bone tumor, but slow progress has been achieved in disentangling the full set of genomic events involved in its initiation and progression. We assessed by NGS the mutational spectrum of 28 primary OSs from Brazilian patients, and identified 445 potentially deleterious SNVs/indels and 1176 copy number alterations (CNAs). TP53 was the most recurrently mutated gene, with an overall rate of ~60%, considering SNVs/indels and CNAs. The most frequent CNAs (~60%) were gains at 1q21.2q21.3, 6p21.1, and 8q13.3q24.22, and losses at 10q26 and 13q14.3q21.1. Seven cases presented CNA patterns reminiscent of complex events (chromothripsis and chromoanasynthesis). Putative RB1 and TP53 germline variants were found in five samples associated with metastasis at diagnosis along with complex genomic patterns of CNAs. PTPRQ, KNL1, ZFHX4, and DMD alterations were prevalent in metastatic or deceased patients, being potentially indicative of poor prognosis. TNFRSF11B, involved in skeletal system development and maintenance, emerged as a candidate for osteosarcomagenesis due to its biological function and a high frequency of copy number gains. A protein–protein network enrichment highlighted biological pathways involved in immunity and bone development. Our findings reinforced the high genomic OS instability and heterogeneity, and led to the identification of novel disrupted genes deserving further evaluation as biomarkers due to their association with poor outcomes.

The general notion of complete hydatidiform moles is that most of them consist entirely of paternal DNA; hence, they do not express p57, a paternally imprinted gene. This forms the basis for the diagnosis of hydatidiform moles. There are about 38 paternally imprinted genes. The aim of this study is to determine whether other paternally imprinted genes could also assist in the diagnostic approach of hydatidiform moles. This study comprised of 29 complete moles, 15 partial moles and 17 non-molar abortuses. Immunohistochemical study using the antibodies of paternal-imprinted (RB1, TSSC3 and DOG1) and maternal-imprinted (DNMT1 and GATA3) genes were performed. The antibodies’ immunoreactivity was evaluated on various placental cell types, namely cytotrophoblasts, syncytiotrophoblasts, villous stromal cells, extravillous intermediate trophoblasts and decidual cells. TSSC3 and RB1 expression were observed in all cases of partial moles and non-molar abortuses. In contrast, their expression in complete moles was identified in 31% (TSSC3) and 10.3% (RB1), respectively (p < 0.0001). DOG1 was consistently negative in all cell types in all cases. The expressions of maternally imprinted genes were seen in all cases, except for one case of complete mole where GATA3 was negative. Both TSSC3 and RB1 could serve as a useful adjunct to p57 for the discrimination of complete moles from partial moles and non-molar abortuses, especially in laboratories that lack comprehensive molecular service and in cases where p57 staining is equivocal.

The article challenges the concept of onychodermis, which is described as an area beneath the nail matrix and nail bed. The authors argue that the concept is confusing and lacks microanatomical basis. They question the claim made by Dr. Lee and colleagues that onychomatricoma is a tumor of onychofibroblasts within the onychodermis. The authors suggest that onychomatricoma is actually a CD34-positive matrix tumor and not an onychofibroblastic tumor. They also discuss their own study on onychomatricoma, which found a link to RB1 loss and suggests the potential diagnostic value of Lef-1. [Extracted from the article]

Background: Spindle cell lipomas, pleomorphic lipomas (SCL/PLs), and pleomorphic fibromas (PF) are tumors with loss of retinoblastoma (RB). The latest World Health Organization classification includes a category of atypical spindle cell/pleomorphic lipomatous tumors (ASPLT), which encompasses tumors in this spectrum that show atypical histopathologic features. We have observed PFs that show similar atypical features. Methods: Cases of SCL/PL and PF with atypical features were collected from tissue archives between 2010 and 2019. Genetic alterations were investigated using array comparative genomic hybridization (aCGH). Result: Of 15 cases found, most tumors were dermal based with fibrocytic or fibroadipocytic appearance and occasional lipoblasts. All cases had a high proliferation index with atypical mitotic figures in 71% of cases. Chromosome 13q loss was present in all cases with CGH data. Additional recurrent chromosomal losses included 17p, 16q, 17q, 20p, 4, and 10. No recurrence was found in limited follow‐up. Conclusions: ASPLTs are characterized by loss of RB, prominent nuclear pleomorphism, mitotic activity including atypical mitotic figures, and genomic instability with multiple chromosomal aberrations. A similar group of tumors with these histopathologic features lacks lipomatous differentiation, and we propose the diagnosis of atypical PF as a fibromatous variant of ASPLT. Limited clinical follow‐up appears benign. [ABSTRACT FROM AUTHOR]

Simple Summary: We treat prostate cancer like it is one disease, but it is clear that it behaves like different diseases in different patients, with some having excellent responses to hormonal therapies and prolonged survivals, and others having virulent, aggressive courses and short survivals. These differences reflect different tumor biologies and therapeutic sensitivities, but the absence of molecular markers that identify each of these subsets makes it difficult to develop treatments specific to each. We found that alterations in two or more of the tumor suppressors TP53, RB1 and PTEN characterize the more virulent prostate cancers, and that patients with this molecular profile (called the aggressive variant prostate cancer molecular profile) appear to benefit more from combination chemotherapies than those without. The alterations in these markers can be determined either by staining tumor tissues or by examining their DNA. In this study, we used 28 mouse models of the human disease to assess the performance of various assays in determining these alterations. We found that although both staining and DNA sequencing are complementary, staining (which is a broadly available technique) is likely sufficient to make these determinations. Our results will inform the use of this molecular signature in clinical research and clinical practice. The aggressive variant prostate cancer molecular profile (AVPC-m), composed of combined defects in TP53, RB1 and PTEN, characterizes a subset of prostate cancers linked to androgen indifference and platinum sensitivity. To contribute to the optimization of the AVPC-m assessment for inclusion in prospective clinical trials, we investigated the status of the AVPC-m components in 28 patient tumor-derived xenografts (PDXs) developed at MDACC. We subjected single formalin-fixed, paraffin-embedded (FFPE) blocks from each PDX to immunohistochemistry (IHC), targeted next-generation genomic sequencing (NGS) and Clariom-S Affymetrix human microarray expression profiling. Standard validated IHC assays and a 10% labeling index cutoff resulted in high reproducibility across three separate laboratories and three independent readers for all tumor suppressors, as well as strong correlations with loss-of-function transcriptional scores (LOF-TS). Adding intensity assessment to labeling indices strengthened the association between IHC results and LOF-TS for TP53 and RB1, but not for PTEN. For TP53, genomic alterations determined by NGS had slightly higher agreement scores with LOF-TS than aberrant IHC, while for RB1 and PTEN, NGS and IHC determinations resulted in similar agreement scores with LOF-TS. Nonetheless, our results indicate that the AVPC-m components can be assessed reproducibly by IHC using various widely available standardized assays. [ABSTRACT FROM AUTHOR]

Diagnosis of pelvic gastrointestinal stromal tumors (GISTs) can be challenging because of their nonspecific presentation and similarity to gynecological neoplasms. In this series, we describe the clinicopathological features of 20 GIST cases: 18 patients presented with pelvic mass and/or abdominal pain concerning gynecological disease; 2 patients presented with a posterior rectovaginal mass or an anorectal mass. Total abdominal hysterectomy and/or salpingo-oophorectomy (unilateral or bilateral) were performed in 13 cases. Gross and histological examination revealed that the ovary/ovaries were involved in three cases, the uterus in two cases, the vagina in two cases and the broad ligament in one case. Immunohistochemically, all tumors (20/20, 100%) were diffusely immunoreactive for c-KIT. The tumor cells were also diffusely positive for DOG-1 (10/10, 100%) and displayed focal to diffuse positivity for CD34 (11/12, 92%). Desmin was focally and weakly expressed in 1 of the 14 tested tumors (1/14, 7%), whereas 2 of 8 tumors (2/8, 25%) showed focal SMA positivity. At the molecular level, 7 of 8 (87.5%) GISTs with molecular analysis contained c-KIT mutations with the second and third c-KIT mutations detected in some recurrent tumors. In addition to c-KIT mutation, a pathogenic RB1 mutation was detected in two cases. We extensively discussed these cases focusing on their differential diagnosis described by the submitting pathologists during consultation. Our study emphasizes the importance of precision diagnosis of GISTs. Alertness to this entity in unusual locations, in combination with clinical history, morphological features as well as immunophenotype, is crucial in leading to a definitive classification. [ABSTRACT FROM AUTHOR]

Cancer development by the human papillomavirus (HPV) infection can occur through the canonical HPV/p53/RB1 pathway mediated by the E2/E6/E7 viral oncoproteins. During the transformation process, HPV inserts its genetic material into host Integration Sites (IS), affecting coding genes and miRNAs. In penile cancer (PeCa) there is limited data on the miRNAs that regulate mRNA targets associated with HPV, such as the TP53 and RB1 genes. Considering the high frequency of HPV infection in PeCa patients in Northeast Brazil, global miRNA expression profiling was performed in high-risk HPV-associated PeCa that presented with TP53 and RB1 mRNA downregulated expression. The miRNA expression profile of 22 PeCa tissue samples and five non-tumor penile tissues showed 507 differentially expressed miRNAs: 494 downregulated and 13 upregulated (let-7a-5p, miR-130a-3p, miR-142-3p, miR-15b-5p miR-16-5p, miR-200c-3p, miR-205-5p, miR-21-5p, miR-223-3p, miR-22-3p, miR-25-3p, miR-31-5p and miR-93-5p), of which 11 were identified to be in HPV16-IS and targeting TP53 and RB1 genes. One hundred and thirty-one and 490 miRNA binding sites were observed for TP53 and RB1 , respectively, most of which were in seedless regions. These findings suggest that up-regulation of miRNA expression can directly repress TP53 and RB1 expression by their binding sites in the non-canonical seedless regions. [ABSTRACT FROM AUTHOR]

Background: Abnormalities in homologous recombination contribute to the aggressive nature of castration-resistant prostate cancer. Retinoblastoma transcriptional corepressor 1 (RB1) and breast cancer 2 (BRCA2) exist close to each other in the same chromosome, and the significance of their concurrent loss has become a hot topic in the field of cancer research. Case presentation: A 61-year-old man presented with a chief complaint of a mass on his head and was diagnosed as multiple bone metastases from prostate cancer. He was treated with standard medication, but he died 2 years 6 months after being diagnosed with prostate cancer. Simultaneous biallelic loss of RB1 and BRCA2 as well as a truncating mutation of tumor protein p53 (TP53) were revealed by genomic analysis. Conclusion: To our knowledge, this is the first report of castration-resistant prostate cancer (CRPC) with BRCA2 and RB1 co-loss and TP53 mutation. To establish a treatment strategy for highly malignant cases with such multiple genetic features is important. [ABSTRACT FROM AUTHOR]

Simple Summary: This review aims to provide an outline of the potential use of plant-based foods, nutraceuticals, and derived micronutrients—particularly those typically found in the Mediterranean diet—as anticancer agents, with a focus on their mechanism of action as cyclin-dependent kinase inhibitors (CDKIs) by inactivating the CDK 4/6 pathway and the regulation of the cell-cycle cascade. We discuss the preclinical and pharmacological significance of some already approved CDK blockers as a promising therapeutic approach against breast and ovarian cancers. Overweight and obesity constitute the most impactful lifestyle-dependent risk factors for cancer and have been tightly linked to a higher number of tumor-related deaths nowadays. The excessive accumulation of energy can lead to an imbalance in the level of essential cellular biomolecules that may result in inflammation and cell-cycle dysregulation. Nutritional strategies and phytochemicals are gaining interest in the management of obesity-related cancers, with several ongoing and completed clinical studies that support their effectiveness. At the same time, cyclin-dependent kinases (CDKs) are becoming an important target in breast and ovarian cancer treatment, with various FDA-approved CDK4/6 inhibitors that have recently received more attention for their potential role in diet-induced obesity (DIO). Here we provide an overview of the most recent studies involving nutraceuticals and other dietary strategies affecting cell-cycle pathways, which might impact the management of breast and ovarian cancers, as well as the repurposing of already commercialized chemotherapeutic options to treat DIO. [ABSTRACT FROM AUTHOR]

Glucose metabolism reprogramming is a critical factor in the progression of multiple cancers and is directly regulated by many tumor suppressors. However, how glucose metabolism regulates osteosarcoma development and progression is largely unknown. Cathepsin K (Ctsk) has been reported to express in chondroprogenitor cells and stem cells besides osteoclasts. Moreover, mutations in the tumor suppressors transformation‐related protein 53 (Trp53) and retinoblastoma protein (Rb1) are evident in approximately 50%–70% of human osteosarcoma. To understand how deletion of Trp53 and Rb1 in Ctsk‐expressing cells drives tumorigenesis, we generated the Ctsk‐Cre;Trp53f/f/Rb1f/f mouse model. Our data revealed that those mice developed osteosarcoma without formation of tumor in osteoclast lineage. The level of cortical bone destruction was gradually increased in parallel to the osteosarcoma progression rate. Through mechanistic studies, we found that loss of Trp53/Rb1 in Ctsk‐expressing cells significantly elevated Yes‐associated protein (YAP) expression and activity. YAP/TEAD1 complex binds to the glucose transporter 1 (Glut1) promoter to upregulate Glut1 expression. Upregulated Glut1 expression led to overactive glucose metabolism, increasing osteosarcoma progression. Ablation of YAP signaling inhibited energy metabolism and delayed osteosarcoma progression in Ctsk‐Cre;Trp53f/f/Rb1f/f mice. Collectively, these findings provide proof of principle that inhibition of YAP activity may be a potential strategy for osteosarcoma treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • p53 and Rb alterations are confirmed as predisposing to SCLC transformation in EGFR- LUAD. • Paired EGFR-LUAD/SCLC samples showed diverse clonal evolution patterns. • TERT amplification is an acquired event during EGFR-LUAD to SCLC transformation. Among the different mechanisms of acquired resistance to EGFR tyrosine kinase inhibitors (TKIs) reported in EGFR -mutated lung adenocarcinoma (EGFR -LUAD) patients, histological transformation into small cell carcinoma (SCLC) occurs in 3–14% of resistant cases, regardless of the generation of EGFR-TKI. In recent studies, bi-allelic inactivation of TP53 and RB1 has been identified in a vast majority of transformed SCLCs. However, the molecular mechanisms driving this histologic transformation remain largely unknown, mainly due to the rarity of samples. Out of an initial cohort of 64 patients, tumor tissues of adequate quality and quantity for whole exome sequencing (WES) analysis were available for nine tumors for six patients: paired pre- and post-SCLC transformation samples for three Patients and post-SCLC transformation samples for three other patients. Mutational analyses showed concurrent TP53 mutations and Rb pathway alterations in five of the six patients analyzed, confirming their suggested role as predisposing genetic alterations to SCLC transformation. In addition, TERT amplification was detected in four of the six patients and found to be an event acquired during SCLC transformation. Clonal history evolution analyses from the paired LUAD/SCLC samples showed different evolution patterns. In two patients, a large proportion of mutations were present in the most recent common ancestor cell of the initial LUAD and the transformed SCLC clones, whereas in the third patient, few clonal mutations were common between the LUAD and SCLC samples and the ancestor clone that lead to SCLC was present at low frequency in the initial LUAD. Despite varied clinical presentations and clonal history evolution patterns, in addition to p53 and Rb pathways alterations, TERT amplification emerged as another common genetic mechanism of EGFR- LUAD to SCLC transformation in our cohort, and could represent a candidate therapeutic target in this subset of SCLC tumors. [ABSTRACT FROM AUTHOR]

Cancer development by the human papillomavirus (HPV) infection can occur through the canonical HPV/p53/RB1 pathway mediated by the E2/E6/E7 viral oncoproteins. During the transformation process, HPV inserts its genetic material into host Integration Sites (IS), affecting coding genes and miRNAs. In penile cancer (PeCa) there is limited data on the miRNAs that regulate mRNA targets associated with HPV, such as the TP53 and RB1 genes. Considering the high frequency of HPV infection in PeCa patients in Northeast Brazil, global miRNA expression profiling was performed in high-risk HPV-associated PeCa that presented with TP53 and RB1 mRNA downregulated expression. The miRNA expression profile of 22 PeCa tissue samples and five non-tumor penile tissues showed 507 differentially expressed miRNAs: 494 downregulated and 13 upregulated (let-7a-5p, miR-130a-3p, miR-142-3p, miR-15b-5p miR-16-5p, miR-200c-3p, miR-205-5p, miR-21-5p, miR-223-3p, miR-22-3p, miR-25-3p, miR-31-5p and miR-93-5p), of which 11 were identified to be in HPV16-IS and targeting TP53 and RB1 genes. One hundred and thirty-one and 490 miRNA binding sites were observed for TP53 and RB1, respectively, most of which were in seedless regions. These findings suggest that up-regulation of miRNA expression can directly repress TP53 and RB1 expression by their binding sites in the non-canonical seedless regions.