RAD21 mutations cause a human cohesinopathy.

The evolutionarily conserved cohesin complex was originally described for its role in regulating sister-chromatid cohesion during mitosis and meiosis. Cohesin and its regulatory proteins have been implicated in several human developmental disorders, including Cornelia de Lange (CdLS) and Roberts syndromes. Here we show that human mutations in the integral cohesin structural protein RAD21 result in a congenital phenotype consistent with a "cohesinopathy." Children with RAD21 mutations display growth retardation, minor skeletal anomalies, and facial features that overlap findings in individuals with CdLS. Notably, unlike children with mutations in NIPBL, SMC1A, or SMC3, these individuals have much milder cognitive impairment than those with classical CdLS. Mechanistically, these mutations act at the RAD21 interface with the other cohesin proteins STAG2 and SMC1A, impair cellular DNA damage response, and disrupt transcription in a zebrafish model. Our data suggest that, compared to loss-of-function mutations, dominant missense mutations result in more severe functional defects and cause worse structural and cognitive clinical findings. These results underscore the essential role of RAD21 in eukaryotes and emphasize the need for further understanding of the role of cohesin in human development.

Clonal wound re-epithelialisation after radiotherapy for skin cancer.

Simple clinical observations can give useful insights into biological processes in humans. Here we present a temporal series of pictures addressing the tissue response of a basal cell carcinoma to radiotherapy, where re-epithelialisation (RE) after radiotherapy appeared to occur by clonal regrowth, rather than the usually described sheet-like RE.

Advanced skin squamous cell carcinoma: role of radiotherapy.

BACKGROUND: We present the case of an elderly man who was referred with a neglected, highly advanced skin squamous cell carcinoma on his posterior chest wall. The cancer was causing difficult-to-control pain and malodour. OBJECTIVE: The treatment and outcomes of local hypofractionated (6 Gray fractions) radiotherapeutic management of an advanced lesion are shown. DISCUSSION: The treatment could not, for reasons of the radiation tolerance of the lungs, cover the entirety of the bulky cancer; ie. the radiotherapy was a balance between not exceeding lung tolerance and achieving adequate tumour coverage. Keeping the treatment simple was also important, as the aim of therapy was palliation, and the patient's ability to lie reproducibly still was compromised. Hence, he was treated with large, weekly fractions - such treatment is useful in the palliative setting, as it minimises patient discomfort and inconvenience. The treatment achieved significant tumour regression, complete relief of pain, arm lymphoedema and a large reduction in malodour.

PET Molecular Imaging in Breast Cancer: Current Applications and Future Perspectives.

Positron emission tomography (PET) plays a crucial role in breast cancer management. This review addresses the role of PET imaging in breast cancer care. We focus primarily on the utility of 18F-fluorodeoxyglucose (FDG) PET in staging, recurrence detection, and treatment response evaluation. Furthermore, we delve into the growing interest in precision therapy and the development of novel radiopharmaceuticals targeting tumor biology. This includes discussing the potential of PET/MRI and artificial intelligence in breast cancer imaging, offering insights into improved diagnostic accuracy and personalized treatment approaches.

Multifocal skin basal cell carcinomata 57 years after topical dry ice treatment.

We report a rare case of simultaneous multiple basal cell carcinomata occurring on the back of a patient who had received dry ice treatment to this area almost 6 decades previously. This is also one of the longest recorded disease-free intervals between skin trauma and basal cell carcinoma development. We discuss the aetiopathology of multiple skin cancers in our patient and the propensity for destructive skin events to predispose to malignancy.

Narrative review-diagnosing and managing malignant epidural spinal cord compression: an evidence-based approach.

Background and Objective: Malignant spinal cord compression (MSCC) is a medical emergency. Clinical deterioration can occur quickly and irreversibly. MSCC is caused predominantly by metastatic cancer spread to the epidural space by epithelial or haematological malignancies. The primary diagnostic test is full-spine magnetic resonance imaging (MRI) since it has excellent soft tissue spatial resolution, and MSCC is multi-level in around one-third of cases. The modalities of therapy for MSCC are steroids, radiotherapy, and surgery. Radiotherapy is a mainstay of treatment since indications for surgery are limited. Recently randomised clinical trials exploring long course vs. short course radiotherapy have been undertaken as well as novel incorporation of stereotactic ablative radiotherapy (SABR). This review summarises these recent trials and identifies and discusses published data for novel treatment paradigms of MSCC. Methods: Multiple medical databases were searched through January 7th, 2023 and identified relevant studies that examined the use of radiotherapy with or without surgery in the management of MSCC. Key Content and Findings: In addition to a detailed overview of the pathophysiology and diagnosis of cord compression, we also examine all recent phase III clinical trials to date on the use of conventional radiotherapy in managing MSCC. Our review also provides a comprehensive summary and discussion of the novel approaches to the management of cord compression, including the role of SABR and a non-traditional surgical approach as well. Conclusions: Shorter courses of radiotherapy can be considered for poor prognosis patients. For favourable prognosis patients, longer courses of treatment provide more durable local control. An emerging treatment paradigm is a hybrid approach of surgery and SABR, however this has not been studied prospectively.

Enhanced RAD21 cohesin expression confers poor prognosis in BRCA2 and BRCAX, but not BRCA1 familial breast cancers.

INTRODUCTION: The RAD21 gene encodes a key component of the cohesin complex, which is essential for chromosome segregation, and together with BRCA1 and BRCA2, for high-fidelity DNA repair by homologous recombination. Although its expression correlates with early relapse and treatment resistance in sporadic breast cancers, it is unclear whether familial breast cancers behave in a similar manner. METHODS: We performed an immunohistochemical analysis of RAD21 expression in a cohort of 94 familial breast cancers (28 BRCA1, 27 BRCA2, and 39 BRCAX) and correlated these data with genotype and clinicopathologic parameters, including survival. In these cancers, we also correlated RAD21 expression with genomic expression profiling and gene copy-number changes and miRNAs predicted to target RAD21. RESULTS: No significant differences in nuclear RAD21 expression were observed between BRCA1 (12 (43%) of 28), BRCA2 (12 (44%) of 27), and BRCAX cancers (12 (33%) of 39 (p = 0.598). No correlation was found between RAD21 expression and grade, size, or lymph node, ER, or HER2 status (all P > 0.05). As for sporadic breast cancers, RAD21 expression correlated with shorter survival in grade 3 (P = 0.009) and but not in grade 1 (P = 0.065) or 2 cancers (P = 0.090). Expression of RAD21 correlated with poorer survival in patients treated with chemotherapy (P = 0.036) but not with hormonal therapy (P = 0.881). RAD21 expression correlated with shorter survival in BRCA2 (P = 0.006) and BRCAX (P = 0.008), but not BRCA1 cancers (P = 0.713). Changes in RAD21 mRNA were reflected by genomic changes in DNA copy number (P < 0.001) and by RAD21 protein expression, as assessed with immunohistochemistry (P = 0.047). High RAD21 expression was associated with genomic instability, as assessed by the total number of base pairs affected by genomic change (P = 0.048). Of 15 miRNAs predicted to target RAD21, mir-299-5p inversely correlated with RAD21 expression (P = 0.002). CONCLUSIONS: Potential use of RAD21 as a predictive and prognostic marker in familial breast cancers is hence feasible and may therefore take into account the patient's BRCA1/2 mutation status.

Mouse HORMAD1 and HORMAD2, two conserved meiotic chromosomal proteins, are depleted from synapsed chromosome axes with the help of TRIP13 AAA-ATPase.

Meiotic crossovers are produced when programmed double-strand breaks (DSBs) are repaired by recombination from homologous chromosomes (homologues). In a wide variety of organisms, meiotic HORMA-domain proteins are required to direct DSB repair towards homologues. This inter-homologue bias is required for efficient homology search, homologue alignment, and crossover formation. HORMA-domain proteins are also implicated in other processes related to crossover formation, including DSB formation, inhibition of promiscuous formation of the synaptonemal complex (SC), and the meiotic prophase checkpoint that monitors both DSB processing and SCs. We examined the behavior of two previously uncharacterized meiosis-specific mouse HORMA-domain proteins--HORMAD1 and HORMAD2--in wild-type mice and in mutants defective in DSB processing or SC formation. HORMADs are preferentially associated with unsynapsed chromosome axes throughout meiotic prophase. We observe a strong negative correlation between SC formation and presence of HORMADs on axes, and a positive correlation between the presumptive sites of high checkpoint-kinase ATR activity and hyper-accumulation of HORMADs on axes. HORMADs are not depleted from chromosomes in mutants that lack SCs. In contrast, DSB formation and DSB repair are not absolutely required for depletion of HORMADs from synapsed axes. A simple interpretation of these findings is that SC formation directly or indirectly promotes depletion of HORMADs from chromosome axes. We also find that TRIP13 protein is required for reciprocal distribution of HORMADs and the SYCP1/SC-component along chromosome axes. Similarities in mouse and budding yeast meiosis suggest that TRIP13/Pch2 proteins have a conserved role in establishing mutually exclusive HORMAD-rich and synapsed chromatin domains in both mouse and yeast. Taken together, our observations raise the possibility that involvement of meiotic HORMA-domain proteins in the regulation of homologue interactions is conserved in mammals.

Radiotherapy planning of lymphomas: role of metabolic imaging with PET/CT.

Accurate target delineation is an absolute requirement for modern radiotherapy planning. Historically, structural imaging modalities have been used for this purpose, but there is a considerable role for functional imaging with PET/CT to contribute in this area. PET/CT's role in radiotherapy planning is well established and its use is indispensable in the clinical management of the lymphomas, particularly Hodgkin Lymphoma. A crucial use of PET/CT is as a baseline scan for delineation of the initial lymphomatous involvement, since this will determine the contouring of the gross-, clinical- and planning-target volumes (GTV, CTV, PTV). This article reviews the principles of contemporary radiotherapy, examines the evidence for the contribution of PET/CT to radiotherapy planning in lymphoma and the practicalities and challenges of applying this powerful technology to this situation.

Bioinformatic analysis of cancer-associated fibroblast related gene signature as a predictive model in clinical outcomes and immune characteristics of gastric cancer.

Background: Gastric cancer (GC) has a high incidence and high mortality rate among Asian countries, and distinguishing predictive prognosis biomarkers for GC are essential. Cancer-associated fibroblasts (CAFs) play a significant role in the progression, immune evasion, and therapeutic resistance of GC. Therefore, CAF-associated genes might have huge potential as prognostic biomarkers for predicting tumor progression and survival rate in GC pateints. Methods: A sum of 1,134 GC patients from the The Cancer Genome Atlas Stomach Adenocarcinoma (TCGA-STAD), GSE62254, and GSE84437 datasets as well as GC cohorts from Xijing hospital were included. Firstly, we performed univariate Cox regression analysis to identify CAF-associated prognostic genes. Subsequently, the Least Absolute Shrinkage and Selection Operator (LASSO) regression analysis was used to develop a CAF gene signature (CAFGS) in the TCGA-STAD training cohort. CAFGS's predictive performance was examined in both the training and validation cohorts, and the relationship between CAFGS and the tumor microenvironment (TME) was investigated by ssGSEA, CIBERSORT, TIMER, and ESTIMATE. Finally, a nomogram of CAFGS was established. Results: Ten CAF-associated genes (ANGPTL4, CPNE8, CST2, HTR1F, IL1RAP, NR1D1, NTAN1, OLFML2B, TMEM259, and VTN) were identified to develop CAFGS. A high CAFGS score represented a worse outcome for GC patients in four cohorts, and a strong correlation was found between CAFGS and the infiltration of immune cells. We showed that CAFs contribute to immune evasion and unfavorable prognoses of GC patients by promoting the formation of an immunosuppressive microenvironment, and a high level of CAF infiltration may attenuate the efficacy of immunotherapy. The nomogram based on CAFGS showed reasonable predictive ability and may deliver great clinical net benefits. Conclusions: We established a CAFGS model with 10 CAF-associated genes that had a great predictive value for GC prognosis and survival rate evaluation. This study could provide a novel insight for investigating the role of CAFs in GC.

Role of ROR2 in promoting gastric cancer metastasis by enhancing c-JUN-mediated MMP3 transcription.

Background: Receptor tyrosine kinase-like orphan receptor 2 (ROR2) is a transmembrane receptor that has a complex role in cancer, acting either to promote or inhibit tumor progression in different tumor types. The effect of ROR2 on gastric cancer is unclear. Methods: Immunohistochemistry was used to investigate the role of ROR2 in the prognosis of gastric cancer. Transwell assay and a BALB/c nude mice pulmonary metastasis model were used to ascertain the role of ROR2 in promoting metastasis in vitro and in vivo. A protein expression array, chromatin immunoprecipitation (ChIP) assay, and luciferase reporter assay were employed to search for the target genes of ROR2. Results: ROR2 was found to be upregulated in gastric cancer tissues, which was correlated with poor disease-free survival (DFS) and overall survival (OS) in gastric cancer patients. Moreover, ROR2 promoted gastric cancer cell migratory and invasive behaviors in vitro and metastasis in vivo. Further research showed that ROR2 promoted gastric cancer metastasis via upregulation of matrix metalloproteinase 3 (MMP3). Analyses of clinical data indicated that high expression of ROR2 was correlated with a high expression of MMP3. Further study showed that ROR2 activated c-JUN by translocating phosphorylated JNK1/2 into the nucleus, and c-JUN interacted directly with the MMP3 promoter, leading to enhanced MMP3 transcription. Conclusions: We report for the first time that ROR2 is upregulated in gastric cancer, promotes metastasis, and is associated with poor prognosis in gastric cancer. The findings suggest that ROR2 may be a promising prognostic predictor for gastric cancer. Silencing the JNK1/2-c-JUN pathway, thereby inhibiting MMP3 expression, may serve as a promising strategy to inhibit gastric cancer progression.

Oncogenic alterations reveal key strategies for precision oncology in melanoma treatment.

Background: Molecular profiling with next-generation sequencing (NGS) has been applied in multiple solid tumors, including melanomas, to identify potential drug targets. However, the association between clinical outcomes and the molecular alterations has not yet been fully clarified. Methods: A total of 108 patients with melanoma were included in this study, 95 of whom had both sequencing data and clinical outcomes were collected. We analyzed the genetic alterations of 108 malignant melanoma patients using the OncoCare panel, which covers 559 genes. Results: A model was also established to predict side effects through a combination analysis of clinical data and somatic variants, yielding an area under the receiver operating characteristic curve (AUROC) score of 0.8. We also identified epidermal growth factor receptor (EGFR) mutation was excellent predictor for progression-free survival (PFS) for patient who received immunotherapy (log-rank P=0.01), while tumor mutation burden (TMB) was found to not be significantly associated with PFS (log-rank P=0.87). Combining clinical features with genetic analysis, we found that patients carrying both DNA POLD1/ALOX12B or POLD1/PTPRT mutations had a significantly lower survival rate. Conclusions: Overall, these results demonstrate the benefits of applying NGS clinical panels and shed light on future directions of personalized therapeutics for the treatment of melanoma.

Enhanced RAD21 cohesin expression confers poor prognosis and resistance to chemotherapy in high grade luminal, basal and HER2 breast cancers.

INTRODUCTION: RAD21 is a component of the cohesin complex, which is essential for chromosome segregation and error-free DNA repair. We assessed its prognostic and predictive power in a cohort of in situ and invasive breast cancers, and its effect on chemosensitivity in vitro. METHODS: RAD21 immunohistochemistry was performed on 345 invasive and 60 pure in situ carcinomas. Integrated genomic and transcriptomic analyses were performed on a further 48 grade 3 invasive cancers. Chemosensitivity was assessed in breast cancer cell lines with an engineered spectrum of RAD21 expression. RESULTS: RAD21 expression correlated with early relapse in all patients (hazard ratio (HR) 1.74, 95% confidence interval (CI) 1.06 to 2.86, P = 0.029). This was due to the effect of grade 3 tumors (but not grade 1 or 2) in which RAD21 expression correlated with early relapse in luminal (P = 0.040), basal (P = 0.018) and HER2 (P = 0.039) groups. In patients treated with chemotherapy, RAD21 expression was associated with shorter overall survival (P = 0.020). RAD21 mRNA expression correlated with DNA copy number, with amplification present in 32% (7/22) of luminal, 31% (4/13) of basal and 22% (2/9) of HER2 grade 3 cancers. Variations in RAD21 mRNA expression in the clinical samples were reflected in the gene expression data from 36 breast cancer cell lines. Knockdown of RAD21 in the MDA-MB-231 breast cancer cell line significantly enhanced sensitivity to cyclophosphamide, 5-fluorouracil and etoposide. The findings for the former two drugs recapitulated the clinical findings. CONCLUSIONS: RAD21 expression confers poor prognosis and resistance to chemotherapy in high grade luminal, basal and HER2 breast cancers. RAD21 may be a novel therapeutic target.

Radiation recall reactions: An oncologic enigma.

Radiation recall reactions (RRR) are uncommon but are a well-known phenomenon to oncologists. Tissue damage in a prior irradiation portal is 'recalled' after the administration of a drug, historically cytotoxics, or more recently, targeted or immunotherapeutic agents. Even COVID-19 vaccines are a reported cause. RRR are enigmatic in that their cause is unknown, but they generally have the histopathological and clinical features of acute or chronic inflammation. They can occur in a variety of tissues, the commonest being skin, which accounts for two-thirds of reported cases. They are generally relatively mild and self-limiting once the trigger drug is stopped, although severe cases with tissue necrosis have occurred. Rechallenge with drug does not necessarily cause reactivation of the reaction. Symptomatic treatment with steroids and antihistamines are usually effective, but their impact on the clinical course is unclear. Various hypotheses have been proposed as to the mechanism of RRR; a non-immune fixed drug reaction-like condition, dysregulated release of reactive oxygen species, abnormalities of tissue vasculature and impaired DNA repair. All could lead to a characteristic inflammatory microenvironment, resulting in dysfunction of tissue stem cells, keratinocyte necrosis and dermal abnormalities. Alternatively or in addition, low levels of inflammatory tissue cytokines induced by previous irradiation might be further upregulated by drug exposure. Most information in this review refers to data derived from cutaneous RRR, since they are the most common form reported.

Pathobiology, irradiation dosimetric parameters and therapy of radiation-induced gastric damage: a narrative review.

OBJECTIVE: To review the pathobiology, irradiation dosimetric parameters and other risk factors, and therapy of radiation-induced gastric damage (RIGD). BACKGROUND: RIGD is a side-effect of upper abdominal radiotherapy. Acute toxicities are usually mild and self-limiting. Late toxicities are potentially life-threatening and include bleeding, perforation or stenosis. The data on RIGD is mainly historical and derived from neoplasms and treatments where the role of radiotherapy is contracting, such as para-aortic nodal irradiation for testis and cervical cancer and Hodgkin's Disease. On the other hand, the role of radiotherapy is expanding, especially with stereotactic body radiotherapy (SBRT) treatments evolving for both primary and secondary upper gastrointestinal neoplasms, which might be expected to increase the frequency of RIGD. Pathoclinical and radiation dosimetric data which might predict the risk of RIGD are evaluated. METHODS: English language articles between 1945 and December 2020, using PubMed and Embase, searching titles for keywords including: radiation; ionizing; radiotherapy; gastritis and 65 articles were selected for review. There may have been a risk of bias in the studies evaluated, since the majority of reports were retrospective, largely descriptive and qualitative. CONCLUSIONS: A common pathoclinical theme in RIGD is inflammation. Numerous factors predict for a greater likelihood of RIGD, including radiation fraction size and dose, concurrent chemotherapy and previous abdominal surgery. Therapy is pathology-dependent and comprises pharmacological, interventional and in the most severe cases, surgical approaches. It is timely to review the topic of RIGD, discuss the limitations of the data and highlight the need for future research directions.

Cutaneous chemotherapy-induced radiation recall reaction.

Chemotherapy-induced radiation recall reactions are rare, commonly affecting skin but can affect internal organs. Treatments include antihistamines and topical steroids and discontinuation of therapy if severe. Rechallenge may not cause recurrence.

Absence of mouse REC8 cohesin promotes synapsis of sister chromatids in meiosis.

REC8 is a key component of the meiotic cohesin complex. During meiosis, cohesin is required for the establishment and maintenance of sister-chromatid cohesion, for the formation of the synaptonemal complex, and for recombination between homologous chromosomes. We show that REC8 has an essential role in mammalian meiosis, in that Rec8 null mice of both sexes have germ cell failure and are sterile. In the absence of REC8, early chromosome pairing events appear normal, but synapsis occurs in a novel fashion: between sister chromatids. This implies that a major role for REC8 in mammalian meiosis is to limit synapsis to between homologous chromosomes. In all other eukaryotic species studied to date, REC8 phenotypes have been restricted to meiosis. Unexpectedly, Rec8 null mice are born in sub-Mendelian frequencies and fail to thrive. These findings illuminate hitherto unknown REC8 functions in chromosome dynamics during mammalian meiosis and possibly in somatic development.

Methylproamine protects against ionizing radiation by preventing DNA double-strand breaks.

PURPOSE: The majority of cancer patients will receive radiotherapy (RT), therefore, investigations into advances of this modality are important. Conventional RT dose intensities are limited by adverse responses in normal tissues and a primary goal is to ameliorate adverse normal tissue effects. The aim of these experiments is to further our understanding regarding the mechanism of radioprotection by the DNA minor groove binder, methylproamine, in a cellular context at the DNA level. MATERIALS AND METHODS: We used immunocytochemical methods to measure the accumulation of phosphorylated H2AX (γH2AX) foci following ionizing radiation (IR) in patient-derived lymphoblastoid cells exposed to methylproamine. Furthermore, we performed pulsed field gel electrophoresis DNA damage and repair assays to directly interrogate the action of methylproamine on DNA in irradiated cells. RESULTS: We found that methylproamine-treated cells had fewer γH2AX foci after IR compared to untreated cells. Also, the presence of methylproamine decreased the amount of lower molecular weight DNA entering the gel as shown by the pulsed field gel electrophoresis assay. CONCLUSIONS: These results suggest that methylproamine acts by preventing the formation of DNA double-strand breaks (dsbs) and support the hypothesis that radioprotection by methylproamine is mediated, at least in part, by decreasing initial DNA damage.

A Roberts Syndrome Individual With Differential Genotoxin Sensitivity and a DNA Damage Response Defect.

PURPOSE: Roberts syndrome (RBS) is a rare, recessively transmitted developmental disorder characterized by growth retardation, craniofacial abnormalities, and truncation of limbs. All affected individuals to date have mutations in the ESCO2 (establishment of cohesion 2) gene, a key regulator of the cohesin complex, which is involved in sister chromatid cohesion and DNA double-strand break (DSB) repair. Here we characterize DNA damage responses (DDRs) for the first time in an RBS-affected family. METHODS AND MATERIALS: Lymphoblastoid cell lines were established from an RBS family, including the proband and parents carrying ESCO2 mutations. Various DDR assays were performed on these cells, including cell survival, chromosome break, and apoptosis assays; checkpoint activation indicators; and measures of DNA breakage and repair. RESULTS: Cells derived from the RBS-affected individual showed sensitivity to ionizing radiation (IR) and mitomycin C-induced DNA damage. In this ESCO2 compound heterozygote, other DDRs were also defective, including enhanced IR-induced clastogenicity and apoptosis; increased DNA DSB induction; and a reduced capacity for repairing IR-induced DNA DSBs, as measured by γ-H2AX foci and the comet assay. CONCLUSIONS: In addition to its developmental features, RBS can be, like ataxia telangiectasia, considered a DDR-defective syndrome, which contributes to its cellular, molecular, and clinical phenotype.