From signalling pathways to targeted therapies: unravelling glioblastoma's secrets and harnessing two decades of progress

Glioblastoma, a rare, and highly lethal form of brain cancer, poses significant challenges in terms of therapeutic resistance, and poor survival rates for both adult and paediatric patients alike. Despite advancements in brain cancer research driven by a technological revolution, translating our understanding of glioblastoma pathogenesis into improved clinical outcomes remains a critical unmet need. This review emphasises the intricate role of receptor tyrosine kinase signalling pathways, epigenetic mechanisms, and metabolic functions in glioblastoma tumourigenesis and therapeutic resistance. We also discuss the extensive efforts over the past two decades that have explored targeted therapies against these pathways. Emerging therapeutic approaches, such as antibody-toxin conjugates or CAR T cell therapies, offer potential by specifically targeting proteins on the glioblastoma cell surface. Combination strategies incorporating protein-targeted therapy and immune-based therapies demonstrate great promise for future clinical research. Moreover, gaining insights into the role of cell-of-origin in glioblastoma treatment response holds the potential to advance precision medicine approaches. Addressing these challenges is crucial to improving outcomes for glioblastoma patients and moving towards more effective precision therapies.

Anoctamins and Calcium Signalling: An Obstacle to EGFR Targeted Therapy in Glioblastoma?

Glioblastoma is the most common form of high-grade glioma in adults and has a poor survival rate with very limited treatment options. There have been no significant advancements in glioblastoma treatment in over 30 years. Epidermal growth factor receptor is upregulated in most glioblastoma tumours and, therefore, has been a drug target in recent targeted therapy clinical trials. However, while many inhibitors and antibodies for epidermal growth factor receptor have demonstrated promising anti-tumour effects in preclinical models, they have failed to improve outcomes for glioblastoma patients in clinical trials. This is likely due to the highly plastic nature of glioblastoma tumours, which results in therapeutic resistance. Ion channels are instrumental in the development of many cancers and may regulate cellular plasticity in glioblastoma. This review will explore the potential involvement of a class of calcium-activated chloride channels called anoctamins in brain cancer. We will also discuss the integrated role of calcium channels and anoctamins in regulating calcium-mediated signalling pathways, such as epidermal growth factor signalling, to promote brain cancer cell growth and migration.

The effects of fructose and metabolic inhibition on hepatocellular carcinoma

Hepatocellular carcinoma is rapidly becoming one of the leading causes of cancer-related deaths, largely due to the increasing incidence of non-alcoholic fatty liver disease. This in part may be attributed to Westernised diets high in fructose sugar. While many studies have shown the effects of fructose on inducing metabolic-related liver diseases, little research has investigated the effects of fructose sugar on liver cancer metabolism. The present study aimed to examine the metabolic effects of fructose on hepatocellular carcinoma growth in vitro and in vivo. Fructose sugar was found to reduce cell growth in vitro, and caused alterations in the expression of enzymes involved in the serine-glycine synthesis and pentose phosphate pathways. These biosynthesis pathways are highly active in cancer cells and they utilise glycolytic by-products to produce energy and nucleotides for growth. Hence, the study further investigated the efficacy of two novel drugs that inhibit these pathways, namely NCT-503 and Physcion. The study is the first to show that the combination treatment of NCT-503 and Physcion substantially inhibited hepatocellular carcinoma growth in vitro and in vivo. The combination of fructose diet and metabolism-inhibiting drugs may provide a unique metabolic environment that warrants further investigation in targeting hepatocellular carcinoma.

A Sweet Connection? Fructose's Role in Hepatocellular Carcinoma

Hepatocellular carcinoma is one of few cancer types that continues to grow in incidence and mortality worldwide. With the alarming increase in diabetes and obesity rates, the higher rates of hepatocellular carcinoma are a result of underlying non-alcoholic fatty liver disease. Many have attributed disease progression to an excess consumption of fructose sugar. Fructose has known toxic effects on the liver, including increased fatty acid production, increased oxidative stress, and insulin resistance. These effects have been linked to non-alcoholic fatty liver (NAFLD) disease and a progression to non-alcoholic steatohepatitis (NASH). While the literature suggests fructose may enhance liver cancer progression, the precise mechanisms in which fructose induces tumor formation remains largely unclear. In this review, we summarize the current understanding of fructose metabolism in liver disease and liver tumor development. Furthermore, we consider the latest knowledge of cancer cell metabolism and speculate on additional mechanisms of fructose metabolism in hepatocellular carcinoma.

The effect of angiopoietin-1 upregulation on the outcome of acute ischaemic stroke in rodent models: A meta-analysis

Clinical studies report that low circulating angiopoietin-1 concentration at presentation predicts worse outcomes after ischaemic stroke. Upregulating angiopoietin-1 may therefore have therapeutic benefit for ischaemic stroke. This systematic review assessed whether upregulating angiopoietin-1 improved outcomes in rodent models of ischaemic stroke. Random-effects models quantified the effect of angiopoietin-1 upregulation on stroke severity in terms of the size of cerebral infarction and the extent of blood-brain barrier permeability. Eleven studies utilising rat and mouse models of ischaemic stroke fulfilled the inclusion criteria. Meta-analyses demonstrated that angiopoietin-1 upregulation significantly reduced cerebral infarction size (standardised mean difference: -3.02; 95% confidence intervals: -4.41, -1.63; p < 0.001; n = 171 animals) and improved blood-brain barrier integrity (standardized mean difference: -2.02; 95% confidence intervals: -3.27, -0.77; p = 0.002; n = 129 animals). Subgroup analyses demonstrated that angiopoietin-1 upregulation improved outcomes in models of transient, not permanent cerebral ischaemia. Six studies assessed the effect of angiopoietin-1 upregulation on neurological function; however, inter-study heterogeneity prevented meta-analysis. In conclusion, published rodent data suggest that angiopoietin-1 upregulation improves outcome following temporary cerebral ischaemia by reducing cerebral infarction size and improving blood-brain barrier integrity. Additional research is required to examine the effect of angiopoietin-1 upregulation on neurological function during stroke recovery and investigate the benefit and risks in patients.

Targeting mTOR and Src restricts hepatocellular carcinoma growth in a novel murine liver cancer model

Liver cancer is a poor prognosis cancer with limited treatment options. To develop a new therapeutic approach, we derived HCC cells from a known model of murine hepatocellular carcinoma (HCC). We treated adiponectin (APN) knock-out mice with the carcinogen diethylnitrosamine, and the resulting tumors were 7-fold larger than wild-type controls. Tumors were disassociated from both genotypes and their growth characteristics evaluated. A52 cells from APN KO mice had the most robust growth in vitro and in vivo, and presented with pathology similar to the parental tumor. All primary tumors and cell lines exhibited activity of the mammalian target of Rapamycin (mTOR) and Src pathways. Subsequent combinatorial treatment, with the mTOR inhibitor Rapamycin and the Src inhibitor Dasatinib reduced A52 HCC growth 29-fold in vivo. Through protein and histological analyzes we observed activation of these pathways in human HCC, suggesting that targeting both mTOR and Src may be a novel approach for the treatment of HCC.

Circulating MicroRNAs as Biomarkers for Acute Ischemic Stroke: A Systematic Review

BACKGROUND

Acute ischemic stroke is a leading cause of death and disability worldwide. Unlike myocardial infarction, there is no current blood test to diagnose acute ischemic stroke. MicroRNAs (miRNAs) are very stable in the blood and have been suggested as potential diagnostic markers.

MATERIALS AND METHODS

This review aimed to systematically assess case-control studies investigating the association of circulating miRNAs with acute ischemic stroke. Medline, CINAHL, Cochrane Library, Web of Science, Scopus, and PubMed were searched for studies that examined the association of circulating miRNAs in patients with acute ischemic stroke. Studies meeting specific inclusion and exclusion criteria (such as blood samples obtained within 24 hours of an acute ischemic stroke) were selected for data extraction. Two authors extracted data from the included studies relevant to the study design, the patient characteristics, and the relative miRNA expression.

RESULTS

Eight studies were included involving 572 cases and 431 healthy controls. Twenty-two miRNAs (12 upregulated and 10 downregulated) were reported as differentially expressed. Only 1 miRNA, miR-106b, was reported as differentially expressed in at least 2 studies. Significant heterogeneity in the design and methods of the included studies was noted.

CONCLUSIONS

Differential expression of a large number of miRNAs has been reported early following acute ischemic stroke. More research is required in larger patient populations to further evaluate the diagnostic potential of the reported miRNAs.

Effect of blood pressure lowering medications on leg ischemia in peripheral artery disease patients: A meta-analysis of randomised controlled trials

BACKGROUND

It has been suggested that anti-hypertensive medications may worsen leg ischemia in peripheral artery disease (PAD) patients. We undertook a meta-analysis to assess the effect of anti-hypertensive medications on measures of leg ischemia including maximum walking distance (MWD), pain free walking distance (PFWD) and ankle brachial pressure index (ABPI). A meta-regression was performed to evaluate whether the effect of the anti-hypertensive medications on mean arterial pressure (MAP) was associated with changes in ABPI, MWD or PFWD.

METHOD

A systematic literature search was performed to identify placebo controlled randomized control trials (RCT) testing anti-hypertensive medications, which reported baseline and follow-up measurements of: MAP and MWD, PFWD or ABPI in patients with intermittent claudication (IC) due to PAD.

RESULT

A meta-analysis was performed on 5 RCTs comprising a total of 180 and 127 patients receiving anti-hypertensive medications and placebo respectively. This analysis suggested that anti-hypertensive medication did not significantly affect MWD, PFWD or ABPI. In contrast, the meta-regression analysis showed that the reduction in MAP due to the anti-hypertensive drugs was positively correlated with increased MWD during follow-up (β = 8.371, p = 0.035). Heterogeneity across studies, as assessed by I2, was high. The follow-up period within the included trials was generally short with 3 out of 5 studies having a follow-up period of ≤ 6 weeks.

CONCLUSION

This study suggests that anti-hypertensive treatment does not worsen but may improve leg ischemia in PAD patients. Larger multicenter trials with longer anti-hypertensive treatment periods are required to clarify the effect of anti-hypertensives on leg ischemia in PAD patients.