Depriving cancer cells of a certain nutrient can effectively kill them, according to a new study which may lead to new therapies for a type of kidney cancer that has historically been difficult to cure.
Cancer cells are notoriously power hungry and they alter their metabolism to provide the additional fuel needed for them to survive, grow and spread.
Researchers at the Duke University in US discovered a promising target for renal cell carcinomas, a form of kidney cancer.
Majority of these cancers rewire their metabolism in a way that leaves them addicted to an outside nutrient called cystine, they said.
By depriving the cancer cells of the amino acid cystine, the researchers were able to trigger a form of cell death called necrosis in mouse models of the disease.
"We found that the same machinery that makes these tumours so aggressive also makes them vulnerable to nutrient deprivation," said senior study author Jen-Tsan Ashley Chi, associate professor of Duke University School of Medicine.
Renal cell carcinoma has historically been very difficult to cure. The disease kills more than 100,000 people a year, researchers said.
About three-fourths of renal cell carcinoma cases are marked by a missing VHL tumour-suppressor gene, which keeps healthy cells from developing into tumours.
Researchers studied how this single genetic change could affect the metabolism and nutrient requirement of cancer cells.
They subjected the cancer cells to a nutrient deprivation test, removing each of the 15 amino acids from their growth media, one by one.
Most of the time, the cells weathered the change quite well, slowing down their growth but otherwise remaining healthy.
However, when cystine was removed, the cells swelled up and floated to the surface, a sure sign of necrotic death.
The researchers then conducted a number of genetic analyses to piece together the network of genes responsible for this nutrient addiction.
Cystine is responsible for maintaining high levels of antioxidants that disarm free radicals of oxygen, researchers found. When they got rid of this nutrient, the cancer cells essentially died by their own hand of free radical damage.
The researchers implanted renal cell carcinoma tumours into mice and then treated the animals with sulfasalazine, a drug that blocks cystine uptake.
They found that the treatment induced necrosis and significantly delayed tumour growth.
The study was published in the journal Cancer Research.
The FMRI registry also analysed data about foreign
patients.
"Of the 617 international patients who came for taking treatment most were from Iraq (65.2 per cent) followed by Nigeria (5.7), Afghanistan (4.4), Uzbekistan (4.4), Kenya (3.1), Congo (2.8), Russia (2.3), Kazakhstan (1.9), Nepal (1.8) and Yemen (1.8)," according to the registry.
The data is checked and validated using quality control programmes and tools followed by cancer registries of the International Agency for Research on Cancer (IARC), the hospital said.
Meanwhile, Gleneagles Global Hospitals today released a report that aims at highlighting the difficulties faced by cancer patients during their journey from diagnosis to treatment.
According to the survey, which spanned six cities-- Bangalore, Mumbai, Delhi, Chennai, Kolkata and Hyderabad. A comprehensive sample of 600 cancer patients and survivors were collected through in person interactions with cancer survivors between the ages of 20-55 years old.
"Respondents in the south India (97 pc) said their family physicians were effective in understanding the symptoms. However, respondents in eastern regions (71 pc), western region (69) and northern region (47) opined that their family physicians could not gauge the signs of cancer to correctly route them to specialists," it said.
Vedant Kabra, Director of Surgical Oncology, FMRI, said, "We must work on preventable strategies along with the treatments. It is a misery to see youngsters impacted by tobacco use and families getting destroyed mentally, financially and socially due to cancers."
"Hazards of tobacco are unlimited. There's no body part which is not affected by it. Smokeless tobacco contains nicotine, which is highly addictive. There are 3,095 chemical components in tobacco, among them 28 are proven carcinogen," he said.
As per the Global Adult Tobacco Survey (GATS) released by the Ministry of Health (2010), around 43 lakhs people above the age of 15 in Haryana (i.E. One in every four individual) are consuming tobacco in some or the other form. One-third of them will be affected by the serious illnesses such as cancer, heart diseases, lung cancers among others and will die premature deaths, the FMRI said.
"While the cancer causing effects of tobacco are well known, most are still unaware of harmful effects of alcohol, areca nut (supari) and obesity. The only way to discourage their usage is to strictly implement Cigarette and Tobacco Product (COTPA) act that aims to prohibit smoking in public places, prohibit sale to minors, stop direct and indirect advertising," says Pankaj Chaturvedi, Professor Surgical Oncology at Tata Memorial Hospital.
