Molecular Mechanisms and Risk Factors for the Pathogenesis of Hydrocephalus

Hydrocephalus is a neurological condition due to the aberrant circulation and/or obstruction of cerebrospinal fluid (CSF) flow with consequent enlargement of cerebral ventricular cavities. However, it is noticed that a lot of patients may still go through symptomatic progression despite standard shunting procedures, suggesting that hydrocephalus is far more complicated than a simple CSF circulative/obstructive disorder. Growing evidence indicates that genetic factors play a fundamental role in the pathogenesis of some hydrocephalus. Although the genetic research of hydrocephalus in humans is limited, many genetic loci of hydrocephalus have been defined in animal models. In general, the molecular abnormalities involved in the pathogenesis of hydrocephalus include brain development and ependymal cell dysfunction, apoptosis, inflammation, free radical generation, blood flow, and cerebral metabolism. Moreover, recent studies have indicated that the molecular abnormalities relevant to aberrant cerebral glymphatic drainage turn into an attractive subject in the CSF circulation disorder. Furthermore, the prevalent risk factors could facilitate the development of hydrocephalus. In this review, we elicited some possible fundamental molecular mechanisms and facilitating risk factors involved in the pathogenesis of hydrocephalus, and aimed to widen the diagnosis and therapeutic strategies for hydrocephalus management. Such knowledge could be used to improve patient care in different ways, such as early precise diagnosis and effective therapeutic regimens.

Blinatumomab In pediatric relapsed/refractory B-cell acute lymphoblastic leukemia: RIALTO expanded access study final analysis

The safety and efficacy of blinatumomab, a CD3/CD19-directed bispecific T-cell engager molecule, for treatment of pediatric relapsed/refractory B-cell precursor acute lymphoblastic leukemia (R/R B-ALL) were examined in an open-label, single-arm, expanded access study (RIALTO). Children (>28 days, <18 years) with CD19+ R/R B-ALL received up to five cycles of blinatumomab by continuous infusion (cycle: 4 weeks on/2 weeks off). The primary endpoint was incidence of adverse events. Secondary endpoints included complete response (CR) and measurable residual disease (MRD) response within the first two cycles, relapse-free survival (RFS), overall survival (OS) and allogeneic hematopoietic stem cell transplant (alloHSCT) after treatment. At final data cutoff (1/10/20), 110 patients were enrolled (median age, 8.5 years; 88% ≥5% blasts at baseline). Blinatumomab treatment resulted in a low incidence of grade 3-4 cytokine release syndrome (n=2 [1.8%]) and neurologic events (n=4 [3.6%]). No blinatumomab-related fatal adverse events were reported. The probability of response was not affected by the presence of cytogenetic/molecular abnormalities. Median OS was 14.6 months (95%CI: 11.0─not estimable) and was significantly greater for MRD responders versus MRD non-responders (not estimable vs 9.3; HR 0.18, 95%CI: 0.08─0.39). One-year OS probability was higher for patients who received alloHSCT versus without alloHSCT post-blinatumomab (87% versus 29%). Median RFS for MRD responders (n=57) was 8.0 months (95%CI:3.4─10.1) versus 2.8 months (95%CI: 0.3─9.2) for MRD non-responders (n=10). Of patients achieving CR after 2 cycles, 73.5% (95%CI: 61.4%-83.5%) proceeded to alloHSCT. These findings support the use of blinatumomab as a safe and efficacious treatment for pediatric R/R B-ALL. (ClinicalTrials.gov identifier NCT02187354)

Heterogeneity in biomarkers, mitogenome and genetic disorders of Arab population with special emphasis on large-scale whole-exome sequencing

More than 25 million DNA variations were discovered as novel including major alleles from Arab population. Exome studies on Arabs discovered >3000 novel nucleotide variants associated with >1200 rare genetic disorders. Reclassification of many pathogenic variant into benign through the Arab database enhance building a detailed and comprehensive map of Arab morbid genome. Intellectual disability stands first with the combined and observed carrier frequency. Genome studies and advanced computational biology discovered interesting novel candidate disease marker variations in many genes from consanguineous families with intellectual disability, neurogenetic disorders, blood and bleeding disorder and rare genetic diseases. Pathogenic variants in C12orf57 gene are prominently associated with the etiology of developmental delay/intellectual impairment. Arab mitogenome exposed hundreds of variations in mtDNA genome and its association with obesity. Further study is needed in genomics to fully comprehend the molecular abnormalities and associated pathogenesis that cause inherited disorders in Arab ancestries.

Pathophysiological Mechanisms in Non-Alcoholic Fatty Liver Disease: From Drivers to Targets

Non-alcoholic fatty liver disease (NAFLD) is characterized by the excessive and detrimental accumulation of liver fat as a result of high-caloric intake and/or cellular and molecular abnormalities. The prevalence of this pathological event is increasing worldwide, and is intimately associated with obesity and type 2 diabetes mellitus, among other comorbidities. To date, only therapeutic strategies based on lifestyle changes have exhibited a beneficial impact on patients with NAFLD, but unfortunately this approach is often difficult to implement, and shows poor long-term adherence. For this reason, great efforts are being made to elucidate and integrate the underlying pathological molecular mechanism, and to identify novel and promising druggable targets for therapy. In this regard, a large number of clinical trials testing different potential compounds have been performed, albeit with no conclusive results yet. Importantly, many other clinical trials are currently underway with results expected in the near future. Here, we summarize the key aspects of NAFLD pathogenesis and therapeutic targets in this frequent disorder, highlighting the most recent advances in the field and future research directions.

Gastric Xanthelasma, Microsatellite Instability and Methylation of Tumor Suppressor Genes in the Gastric Mucosa: Correlation and Comparison as a Predictive Marker for the Development of Synchronous/Metachronous Gastric Cancer

A predictive marker for the development of synchronous/metachronous gastric cancer (GC) would be highly desirable in order to establish an effective strategy for endoscopic surveillance. Herein, we examine the significance of gastric xanthelasma (GX) and molecular abnormalities for the prediction of synchronous/metachronous GC. Patients (n = 115) were followed up (range, 12–122; median, 55 months) in whom the presence of GX and molecular alterations, including microsatellite instability (MSI) and methylation of human mutL homolog 1 (hMLH1), cyclin-dependent kinase inhibitor 2A (CDKN2A) and adenomatous polyposis coli (APC) genes, had been confirmed in non-neoplastic gastric mucosa when undergoing endoscopic submucosal dissection (ESD) for early GC. At the start of surveillance, the numbers of positive subjects were as follows: GX, 59 (51.3%); MSI, 48 (41.7%); hMLH1, 37 (32.2%); CDKN2A, 7 (6.1%); APC, 18 (15.7%). After ESD treatment, synchronous/metachronous GCs occurred in patients with the following positive factors: GX, 16 (27.1%); MSI, 7 (14.6%); hMLH1, 6 (16.2%); CDKN2A, 3 (42.9%); APC, 3 (16.7%). The presence of GX had no significant relationship to positivity for MSI or methylation of hMLH1, CDKN2A or APC. GX was significantly (p = 0.0059) and independently (hazard ratio, 3.275; 95% confidence interval, 1.134–9.346) predictive for the development of synchronous/metachronous GC, whereas those genetic alterations were not predictive. GX is a simple and powerful marker for predicting the development of synchronous or metachronous GC.

MET Gene Dysregulation as a Promising Therapeutic Target in Lung Cancer—A Review

Several molecular abnormalities in the MET gene have been identified, including overexpression, amplification, point mutations, and “skipping mutation” in exon 14. Even though deregulated MET signaling occurs rarely in non-small cell lung cancer (NSCLC), it possesses tumorigenic activity. Since the discovery of the significant role played by MET dysregulations in resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKI), many clinical trials have been focused on mechanisms underlying this acquired resistance. Therefore, new therapeutic strategies are being considered in the personalized therapy of NSCLC patients carrying MET abnormalities. First, MET kinase inhibitors (tepotinib and capmatinib) have been shown to be effective in the first and subsequent lines of treatment in NSCLC patients with “skipping mutations” in exon 14 of MET gene. In this article, the authors show the role of MET signaling pathway alterations and describe the results of clinical trials with MET inhibitors in NSCLC patients.

The Dawn of next generation DNA sequencing in myelodysplastic syndromes- experience from Pakistan

Background Myelodysplastic syndromes (MDS) are clonal disorders of hematopoietic stem cells exhibiting ineffective hematopoiesis and tendency for transformation into acute myeloid leukemia (AML). The available karyotyping and fluorescent in situ hybridization provide limited information on molecular abnormalities for diagnosis/prognosis of MDS. Next generation DNA sequencing (NGS), providing deep insights into molecular mechanisms being involved in pathophysiology, was employed to study MDS in Pakistani cohort. Patients and methods It was a descriptive cross-sectional study carried out at National institute of blood diseases and bone marrow transplant from 2016 to 2019. Total of 22 cases of MDS were included. Complete blood counts, bone marrow assessment and cytogenetic analysis was done. Patients were classified according to revised WHO classification 2016 and IPSS score was applied for risk stratification. Baseline blood samples were subjected to analysis by NGS using a panel of 54 genes associated with myeloid malignancies. Results The median age of patients was 48.5 ± 9.19 years. The most common presenting complaint was weakness 10(45.45%). Cytogenetics analysis revealed abnormal karyotype in 10 (45.45%) patients. On NGS, 54 non-silent rare frequency somatic mutational events in 29 genes were observed (average of 3.82 (SD ± 2.08) mutations per patient), including mutations previously not observed in MDS or AML. Notably, two genes of cohesin complex, RAD21 and STAG2, and two tumor suppressor genes, CDKN2A and TP53, contained highest number of recurrent non-silent somatic mutations in the MDS. Strikingly, a missense somatic mutation p.M272Rof Rad21 was observed in 13 cases. Overall, non-silent somatic mutations in these four genes were observed in 21 of the 22 cases. The filtration with PharmGKB database highlighted a non-synonymous genetic variant rs1042522 [G > C] located in the TP53. Genotype GG and GC of this variant are associated with decreased response to cisplatin and paclitaxel chemotherapy. These two genotypes were found in 13 cases. Conclusion Sequencing studies suggest that numerous genetic variants are involved in the initiation of MDS and in the development of AML. In countries like Pakistan where financial reservation of patients makes the use of such analysis even more difficult when the availability of advanced techniques is already a prevailing issue, our study could be an initiating effort in adding important information to the local data. Further studies and large sample size are needed in future to enlighten molecular profiling and ultimately would be helpful to compare and contrast the molecular characteristics of Asian versus global population.

Primary Chondrosarcoma in L-shaped Crossed Fused Renal Ectopia Coexisting with Papillary Urothelial Carcinoma in Urinary Bladder

Primary renal chondrosarcomas are rare tumors that are high-grade in nature and, unfortunately, have poorly understood pathogenesis and extremely low prognosis. The coexistence of a discrete malignancy in the urinary bladder is even rarer, with the occurrence of distinct papillary urothelial carcinoma in the urinary bladder in this case. The clinical presentation is nonspecific, and the primary radiological investigations have a limited scope in providing specific diagnosis of this entity. The final diagnosis is possible on thorough histopathological examination of the resected specimen, which requires extensive sampling and meticulous reporting. As of now, the only way to achieve a better prognosis is by early diagnosis. It is necessary to keep the possibility of occurrence of sarcomas at rare sites in the differential diagnoses. The cytogenetic and molecular abnormalities associated with this entity need to be elucidated to achieve a more satisfactory outcome concerning the overall management of the patient.

Chromothripsis in Chronic Lymphocytic Leukemia: A Driving Force of Genome Instability

Chromothripsis represents a mechanism of massive chromosome shattering and reassembly leading to the formation of derivative chromosomes with abnormal functions and expression. It has been observed in many cancer types, importantly, including chronic lymphocytic leukemia (CLL). Due to the associated chromosomal rearrangements, it has a significant impact on the pathophysiology of the disease. Recent studies have suggested that chromothripsis may be more common than initially inferred, especially in CLL cases with adverse clinical outcome. Here, we review the main features of chromothripsis, the challenges of its assessment, and the potential benefit of its detection. We summarize recent findings of chromothripsis occurrence across hematological malignancies and address its causes and consequences in the context of CLL clinical features, as well as chromothripsis-related molecular abnormalities described in published CLL studies. Furthermore, we discuss the use of the current knowledge about genome functions associated with chromothripsis in the optimization of treatment strategies in CLL.