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Biology subjects

Wong, J. P.

Publications and source records attributed to Wong, J. P..

3 recordsLinked to original sources

EGR1 drives sex-differences in glioblastoma tumorigenicity

Although progress has been made in treating glioblastoma (GBM), with fewer than 5% of patients surviving more than 5 years after diagnosis. For reasons that are not well understood, females are roughly 60% as likely as males to develop GBM, and female patients consistently respond better to treatment than do males. Understanding the molecular etiology of these sex differences in tumor progression and resiliency to treatment could reveal potent new therapeutic targets, ultimately improving survival of both male and female GBM patients. Here we show that the transcription factor Egr1 is a primary mediator of sex differences in multiple GBM tumorigenic phenotypes. In multivariate analysis, high levels of EGR1 expression are correlated with shortened survival for male GBM patients only. To investigate the molecular mechanisms underlying this sex difference, we performed a genomic analysis in our established ex vivo murine model of sex differences, which showed that the transcription factors Egr1 and Klf5 preferentially recruit the transcriptional activator Brd4 to enhancers in male cells relative to female cells, explaining a previously made observation that Brd4 inhibitors reverse sex differences in GBM. Next, using murine and human primary GBM cells, we demonstrated that the small molecule compound SR18662, which downregulates Egr1 and its downstream target Klf5, abrogates GBM growth, migration, invasion, clonogenicity, and response to radiation in a sex-biased fashion. Finally, we knocked down Egr1 and Klf5 via CRISPRi in both untreated and SR18662-treated GBM cells to reveal the sex-biased anti-tumorigenic effects of SR18662 were largely due to Egr1 downregulation, independent of Klf5 downregulation. This result was replicated in vivo. Our results strongly indicate that an Egr1 regulon is a key determinant of sex differences in GBM. As EGR1 is implicated in the cancer biology of many cancers that also display sex differences in incidence and treatment response, our results are likely to be broadly applicable in oncology.

cancer biology↗

High-density amplicon sequencing identifies community spread and ongoing evolution of SARS-CoV-2 in the Southern United States

SARS-CoV-2 is constantly evolving. Prior studies have focused on high case-density locations, such as the Northern and Western metropolitan areas in the U.S. This study demonstrates continued SARS-CoV-2 evolution in a suburban Southern U.S. region by high-density amplicon sequencing of symptomatic cases. 57% of strains carried the spike D614G variant. The presence of D614G was associated with a higher genome copy number and its prevalence expanded with time. Four strains carried a deletion in a predicted stem loop of the 3 untranslated region. The data are consistent with community spread within the local population and the larger continental U.S. No strain had mutations in the target sites used in common diagnostic assays. The data instill confidence in the sensitivity of current tests and validate "testing by sequencing" as a new option to uncover cases, particularly those not conforming to the standard clinical presentation of COVID-19. This study contributes to the understanding of COVID-19 by providing an extensive set of genomes from a non-urban setting and further informs vaccine design by defining D614G as a dominant and emergent SARS-CoV-2 isolate in the U.S.

microbiology↗

Primary cilia mediate diverse kinase inhibitor resistance mechanisms in cancer

Primary cilia are microtubule-based organelles that detect mechanical and chemical stimuli. Although cilia house a number of oncogenic molecules (including Smoothened, KRAS, EGFR, and PDGFR), their precise role in cancer remains unclear. We have interrogated the role of cilia in acquired and de novo resistance to a variety of kinase inhibitors, and found that in several examples, resistant cells are distinctly characterized by an increase in the number and/or length of cilia with altered structural features. Changes in cilia length seem to be linked to the lack of recruitment of Kif7 and IFT81 to cilia tips, and result in enhanced hedgehog pathway activation. Notably, Kif7 knockdown is sufficient to confer drug resistance in drug sensitive cells. Conversely, targeting of cilia length or integrity through genetic and pharmacological approaches overcomes kinase inhibitor resistance. The identification of a broad mechanism of pathway-unbiased drug resistance, represents a major advancement in oncology, and helps define a specific and important role for cilia in human cancer.

cell biology↗