Rottlerin induces autophagy and apoptosis in prostate cancer stem cells via PI3K/Akt/mTOR signaling pathway

Dhruv Kumar, Sharmila Shankar, Rakesh K Srivastava
Cancer Letters 2014 February 28, 343 (2): 179-89
Autophagy plays an important role in cellular homeostasis through the disposal and recycling of cellular components. Cancer stem cells (CSCs) play major roles in cancer initiation, progression, and drug resistance. Rottlerin (Rott) is an active molecule isolated from Mallotus philippinensis, a medicinal plant used in Ayurvedic Medicine for anti-allergic and anti-helminthic treatments, demonstrates anticancer activities. However, the molecular mechanisms by which it induces autophagy in prostate CSCs have not been examined. The main objective of the paper was to examine the molecular mechanisms by which Rott induces autophagy in prostate CSCs. Autophagy was measured by the lipid modification of light chain-3 (LC3) and the formation of autophagosomes. Apoptosis was measured by flow cytometer analysis. The Western blot analysis was used to examine the effects of Rott on the expression of PI3K, phosphorylation of Akt, phosphorylation of mTOR, and phosphorylation of AMPK in pros CSCs. RNAi technology was used to inhibit the expression of Beclin-1 and ATG-7. Rott induced the lipid modification of light chain-3 (LC3) and the formation of autophagosomes after 24h of Rott treatment in prostate CSCs. Rott-treated prostate CSCs induced transition from LC3-I to LC3-II, a hall mark of autophagy. Rott also induced the expression of Atg5, Atg7, Atg12 and Beclin-1 proteins during autophagy. The knock-down of Atg7 and Beclin-1 blocked Rott-induced autophagy. Furthermore, Rott induced AMPK phosphorylation was blocked by 3-MA, Baf and CHX. In addition, inhibition of AMPK expression by shRNA blocked Rott induced autophagy. In conclusion, a better understanding of the biology of autophagy and the pharmacology of autophagy modulators has the potential for facilitating the development of autophagy-based therapeutic interventions for prostate cancer.

Full Text Links

Find Full Text Links for this Article


You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read

Save your favorite articles in one place with a free QxMD account.


Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"