English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Lymphangioleiomyomatosis (LAM) is a rare metastatic cystic lung disease due to a mutation in a TSC tumor suppressor, resulting in hyperactive mTOR growth pathways. Sirolimus (rapamycin), an allosteric mTORC1 inhibitor, is a therapeutic option for women with LAM but it only maintains lung volume during treatment and does not provide benefit for all LAM patients. The two major mTORC1 protein synthesis pathways are via S6K/S6 or 4E-BP/eIF4E activation. We aimed to investigate rapamycin in combination with compounds that target associated growth pathways, with the potential to be additive to rapamycin. In this study we demonstrated that rapamycin, at a clinically tolerable concentration (10 nM), inhibited the phosphorylation of S6, but not the critical eIF4E releasing Thr 37/46 phosphorylation sites of 4E-BP1 in TSC2-deficient LAM-derived cells. We also characterized the abundant protein expression of peIF4E within LAM lesions. A selective MNK1/2 inhibitor eFT508 inhibited the phosphorylation of eIF4E but did not reduce TSC2-null cell growth. In contrast, a PI3K/mTOR inhibitor omipalisib blocked the phosphorylation of Akt and both S6K/S6 and 4E-BP/eIF4E branches, and additively decreased the growth of TSC2-null cells with rapamycin. Omipalisib, or another inhibitor of both major mTORC1 growth pathways and pAkt, might provide therapeutic options for TSC2-deficient cancers including, but not limited to, LAM.

Inhibition of Growth of TSC2-Null Cells by a PI3K/mTOR Inhibitor but Not by a Selective MNK1/2 Inhibitor