New research just published in Integrative Cancer Therapies shows that the Pao pereira plant extract inhibits pancreatic cancer stem cells. This dramatic result means that the extract will be useful for preventing cancer recurrence.
Everyone knows that cancer treatments are not cancer cures. Chemotherapy treatments kill cancer cells and shrink tumors, but the cancer often comes back. Cancer stem cells (CSCs) are the culprit because they are resistant to anti-cancer drugs, they can metastasize and form new tumors. CSCs make up a small fraction of the cells in a tumor that survive after the majority of primary cancer cells are killed by anti-cancer drugs. The CSCs persist, spread and restart tumor growth.
CSCs are also referred to as cancer stem-like cells because they share the capacity for self-proliferation with normal stem cells that are involved in the renewal and repair of tissues, but unlike normal stem cells, CSCs are cancerous and drug resistant.
In vitro experiments show Pao pereira reducing the number of pancreatic CSCs (see figure below).
As the amount of Pao pereira is increased, the number of pancreatic cancer stem cells (spheroids) decrease dramatically. In additional cell-based studies, the Pao pereira extract also specifically reduced the pancreatic cancer stem cell population.
In vivo experiments showed that Pao pereira inhibited the capacity of pancreatic CSCs to form tumors – the defining characteristic of CSCs – and significantly reduce the volume of tumors that did form (see figure below).
At day 6 (Figure A), tumor formation rate in the control group reached 80%, while in Pao-treated group it was only 10%. At day 20, when the treatment stopped, all mice in control group were bearing tumors on both flanks (100% tumor formation), while the Pao-treated group only had 30% tumor formation. Growth of the formed tumors was also inhibited by Pao pereira treatment compared with the control group (Figure B). A long-term inhibitory effect in tumor growth was observed after treatment had stopped. Pao pereira works by lowering the signals that trigger the pancreatic cancer stem-like cell properties that lead to cancer recurrence.
The researchers at Kansas University Medical Center concluded that Pao pereira holds great promise as a novel treatment for targeting pancreatic CSCs, an essential component of treatments that will lead to real cancer cures.