bioRxiv Science⌕ Search

Biology subjects

Raleigh, M.

Publications and source records attributed to Raleigh, M..

2 recordsLinked to original sources

Novel sex-biased outcomes in neuroblastoma are associated with distinct gene expression and chromosomal loss patterns.

The worst patient outcomes in neuroblastoma are driven by high-risk disease1,2, which is divided into similarly sized MYCN amplified and MYCN non-amplified patient subgroups3. Male patients have been reported to have slightly worse outcomes than females in all-patient analyses of multiple studies3,4. However, we show here that in MYCN non- amplified high-risk and stage 4s low-risk disease, female patients have significantly worse overall survival than males. Female MYCN non-amplified high-risk patients highly express H19 and DLK1, both of which drive cell growth in vitro and are associated with worse outcomes in females but not males. Further, chromosome-specific expression analysis of these patients reveals broad sex disparities in chromosomal patterning, including female-specific retention of chromosome 11q, a pattern typically reserved for MYCN-amplified disease5,6. Finally, we show that H19, a known let-7 microRNA target7, sequesters let-7 in females, providing a rationale for worse female survival and reconciling retention of chromosome 11q. We propose that this novel sex-based outcome disparity is driven by let-7 inhibition, expanding on a model of neuroblastoma development where let-7 mitigation is central to disease pathology8.

cancer biology↗

High dose ω3 eicosapentaenoic acid and docosahexaenoic acid block, whereas ω6 arachidonic acid accelerates, MYCN-driven tumorigenesis in vivo

Background/ObjectivesNeuroblastoma is a genetically diverse, highly metastatic pediatric cancer accounting for 15% of childhood cancer deaths despite only having ~8% of childhood cancer incidence. The current standard of care for high-risk disease is highly genotoxic. This, combined with less than 50% survival in high-risk disease and an abysmal 5% survival in relapsed cases, makes discovering novel, effective, and less toxic treatments essential. MethodsA prophylactic syngeneic mouse model was used to test high-dose lipid-mediator highly unsaturated fatty acids on tumorigenesis. Wild-type mice were gavaged with 12.3-14.6 g/d (adult human equivalent) omega-3 EPA, DHA, or oxidation-resistant bis allylic deuterated DHA (D-DHA) and 4.6-6.0 g/d arachidonic acid (ARA). At seven days, MYCN-expressing murine neuro-2a cells syngeneic to the gavaged mice were injected subcutaneously. Oral gavage continued for 10-20 d post-injection when tumors and tissues were harvested. ResultsFifty percent of control (not gavaged) animals form tumors (4/8) at about 10 d. High-dose DHA, D-DHA, and EPA block tumor formation completely in n=8 or 10 animals. In contrast, {omega}6 arachidonic acid (4.6-6.0 g/d) enhances tumor formation (6/10 tumors) and reduces latency (5.5 to 10 days)compared to control. Co-delivery of ARA and EPA results in a reduced tumor burden analogous to the control group, suggesting that EPA directly opposes the mechanism of ARA-mediated tumor formation. DHA acts through a non-oxidative mechanism. ConclusionsSustained high dose {omega}3 (weeks/months) is safe and well tolerated in humans. These results suggest that {omega}3 DHA and EPA delivery at ultra-high doses may represent a viable low-toxicity therapy for neuroblastoma. Simple SummaryPediatric Neuroblastoma has an overall mortality rate above 50%, and the current standard of care consists of highly genotoxic compounds. The biological actions of omega-6 ({omega}6) and omega-3 ({omega}3) highly unsaturated fatty acids (HUFA) generally oppose one another with the {omega}6 HUFA signaling for inflammation and angiogenesis (new blood vessel formation). Prolonged use of ultrahigh dose (15-20 g/d) {omega}3 HUFA has shown efficacy in catastrophic human traumatic brain injury and is well tolerated. Tumors form in about 50% of mice in our pediatric neuro-blastoma model. We show that 12-14 g/d adult human equivalent doses of {omega}3 EPA or DHA, as well as an oxidation-resistant form of DHA (D-DHA), completely block tumor formation, whereas a dose of about 5 g/d of {omega}6 ARA enhances tumorigenesis. Our data suggest that ultra-high dose {omega}3 therapy should be carefully investigated as a low-toxicity approach to neuroblastoma intervention.

cancer biology↗