JNK Kinase regulates cachexia like syndrome in scribble knockdown tumor model of Drosophila melanogaster

Area of Science:

• Molecular Biology
• Cancer Research
• Genetics

Background:

• Cachexia and systemic organ wasting are metabolic syndromes frequently linked to cancer, but their precise mechanisms remain unclear.
• Scribble (scrib), a cell polarity regulator and tumor suppressor, is often lost or mis-localized in various cancers, including breast, colon, and prostate cancer.

Purpose of the Study:

• To investigate the role of JNK kinase in cancer-associated cachexia-like syndrome using a fly model.
• To explore the potential of targeting JNK signaling as a therapeutic strategy for cachexia.

Main Methods:

• Utilized a Drosophila melanogaster model with induced hindgut tumors via scribble (scrib) knockdown.
• Assessed male lethality, lifespan, systemic organ wasting, and phosphorylated JNK (pJNK) levels.
• Investigated the effect of knocking down the JNK kinase analogue, hep, in the scrib knockdown background.

Main Results:

• Scrib knockdown in flies induced male lethality, reduced lifespan, systemic organ wasting, and increased pJNK levels in the hindgut.
• Knocking down hep in the scrib knockdown background restored normal lifespan and reduced organ wasting, indicating JNK pathway involvement.
• Scrib loss in the hindgut was shown to induce a cachexia-like syndrome, including gut barrier disruption.

Conclusions:

• The study demonstrates that scribble loss in the hindgut can trigger cancer-associated cachexia-like syndrome.
• Blocking the JNK signaling pathway effectively rescued cachexia and gut barrier disruption induced by scrib knockdown.
• These findings offer new insights into cancer cachexia mechanisms and suggest JNK signaling as a potential therapeutic target.