4.7 Role of Phytochemicals in Cancer Cure Via
Regulation of miRNA
Cancer has become an extensive malicious disease that relies greatly on the treatment of chemotherapy. The chemotherapy drugs, however, not only contrives the
intensity to cause deleterious side effects, but also triggers tumour regression after a
temporary period of improvement. Strange enough, these relapsed cancer cells
enhance their survival propensity by being chemoresistance. Hence, critical measurements are indispensable to pursue an agent without or with minimal side effects.
Nature endows vegetables, fruits and herbs with chemical properties called phytochemicals possessing the aptitude in treating cancer, infections and healing
proneness. These phytochemicals are found copious from a wide range of plant
products and of these, 10,000 compounds were documented and described (Russo
et al. 2010). Some of these chemicals displayed anticancer potential with almost
zero or minimal cytotoxicity to normal cell physiology (Rao et al. 2007).
Enigmatically, 47% of drugs ratified by FDA are of plant origin that can be treated
as single chemotherapeutic agent usage or by merging with other standard anticancer drugs (Newman and Cragg 2007).
When phytochemicals are exerting anticancer properties, various questions
emerged in connection to microRNA’s role and regulation. The miRNAs some time
back had been linked with oncogenic and tumour suppressor action, serving a
perfect goal in cancer deterrence and therapy. The explicate mechanism that
involves anomalous expression of miRNAs discovered in many cancer types has
yet to be determined. Mounting data implicates anomalous transcription machinery,
epigenetic and miRNA biosynthesis alteration, mutations or the presence of different DNA number to be prompting miRNA dysregulation in human cancer (Deng
et al. 2008). Nonetheless, researchers exposed the potentiality of phytochemicals in
the modulation miRNA expression and their effect in cancer pathobiology.
There were several studies revealing the modus operandi of phytochemicals in
regulating miRNA expression with an exception to transcriptional regulation.
Epigallocatechin-3-gallate (EGCG) is a rich constituent and the most efficient
catechin in green tea where its role has been contributed to cancer treatment
(Mukherjee et al. 2015). This compound was reported to incite the binding of
hypoxia inducible factor-1a (HIF-1a) to the promoter region of miR-210, eventually deceiving the cells to stop cell proliferation and anchorage-independent growth
as noted in human non-small cell lung cancer cell lines, H1299, H460 and A549
(Wang et al. 2011). Coincidingly, Yamada et al. (2016) had remarkable discovery
on EGCG upregulating miRNA-let-7b which then activated 67 kDa laminin
receptor to inhibit cancer growth in B16 melanoma cells. Of late, ECGC was also
demonstrated to down-regulate the expression of miR-25 and escalate PARP,
pro-caspase-3 and pro-caspase-9 inducing cell apoptosis in MCF- 7 cells (Zan et al.
2019).
The resveratrol has long been insinuated in the treatment of cancer and other
diseases. In human colon cancer study, resveratrol significantly reduced the level of
4 The Role of Phytochemicals in Cancer Prevention and Cure
139
Regulation of miRNA
Cancer has become an extensive malicious disease that relies greatly on the treatment of chemotherapy. The chemotherapy drugs, however, not only contrives the
intensity to cause deleterious side effects, but also triggers tumour regression after a
temporary period of improvement. Strange enough, these relapsed cancer cells
enhance their survival propensity by being chemoresistance. Hence, critical measurements are indispensable to pursue an agent without or with minimal side effects.
Nature endows vegetables, fruits and herbs with chemical properties called phytochemicals possessing the aptitude in treating cancer, infections and healing
proneness. These phytochemicals are found copious from a wide range of plant
products and of these, 10,000 compounds were documented and described (Russo
et al. 2010). Some of these chemicals displayed anticancer potential with almost
zero or minimal cytotoxicity to normal cell physiology (Rao et al. 2007).
Enigmatically, 47% of drugs ratified by FDA are of plant origin that can be treated
as single chemotherapeutic agent usage or by merging with other standard anticancer drugs (Newman and Cragg 2007).
When phytochemicals are exerting anticancer properties, various questions
emerged in connection to microRNA’s role and regulation. The miRNAs some time
back had been linked with oncogenic and tumour suppressor action, serving a
perfect goal in cancer deterrence and therapy. The explicate mechanism that
involves anomalous expression of miRNAs discovered in many cancer types has
yet to be determined. Mounting data implicates anomalous transcription machinery,
epigenetic and miRNA biosynthesis alteration, mutations or the presence of different DNA number to be prompting miRNA dysregulation in human cancer (Deng
et al. 2008). Nonetheless, researchers exposed the potentiality of phytochemicals in
the modulation miRNA expression and their effect in cancer pathobiology.
There were several studies revealing the modus operandi of phytochemicals in
regulating miRNA expression with an exception to transcriptional regulation.
Epigallocatechin-3-gallate (EGCG) is a rich constituent and the most efficient
catechin in green tea where its role has been contributed to cancer treatment
(Mukherjee et al. 2015). This compound was reported to incite the binding of
hypoxia inducible factor-1a (HIF-1a) to the promoter region of miR-210, eventually deceiving the cells to stop cell proliferation and anchorage-independent growth
as noted in human non-small cell lung cancer cell lines, H1299, H460 and A549
(Wang et al. 2011). Coincidingly, Yamada et al. (2016) had remarkable discovery
on EGCG upregulating miRNA-let-7b which then activated 67 kDa laminin
receptor to inhibit cancer growth in B16 melanoma cells. Of late, ECGC was also
demonstrated to down-regulate the expression of miR-25 and escalate PARP,
pro-caspase-3 and pro-caspase-9 inducing cell apoptosis in MCF- 7 cells (Zan et al.
2019).
The resveratrol has long been insinuated in the treatment of cancer and other
diseases. In human colon cancer study, resveratrol significantly reduced the level of
4 The Role of Phytochemicals in Cancer Prevention and Cure
139