VARIOUS STUDIES SHOW NEW TREATMENTS FOR CANCERS MAY SOON BE ON THE RADAR.
The current most common types of cancer treatment are chemotherapy, radiotherapy, tumour surgery and (for prostate and breast cancer) hormonal therapy.
However medicalnewstoday.com reports ‘other types of treatment are beginning to pick up steam: therapies that – on their own or in combination with other treatments – are meant to help defeat cancer more efficiently and, ideally, have fewer side effects’. These include:
IMMUNOTHERAPY
Immunotherapy ‘aims to reinforce our own bodies’ existing arsenal against foreign bodies and harmful cells: our immune system’s response to the spread of
cancer tumors’.
Previously many types of cancer cell have been particularly dangerous because they have ways of ‘duping’ the immune system – either into ignoring them altogether or giving them a ‘helping hand’. As a result, some types of aggressive cancer have been able to spread more easily and become resistant to chemotherapy or radiotherapy. However researchers are now learning how they might be able to ‘deactivate’ the cancer cells’ protective systems.
A study in Nature Immunology found macrophages, or white blood cells, that are normally tasked with ‘eating up’ cellular debris and other harmful foreign ‘objects’ failed to obliterate the super-aggressive cancer cells – because, in their interaction with the cancer cells, the macrophages read not one but two signals meant to repel their ‘cleansing’ action.
This knowledge showed the scientists the way forward: by blocking the two relevant signalling pathways, they re-enabled the white blood cells to do their work.
THERAPEUTIC VIRUSES
A UK team managed to use a reovirus to attack brain cancer cells while leaving healthy cells alone.
The team noted: ‘This is the first time it has been shown that a therapeutic virus is able to pass through the brain-blood barrier’ which ‘opens up the possibility this type of immunotherapy could be used to treat more people with aggressive brain cancers.’
DENDRITIC VACCINES
A strategy where dendritic cells (which play a key role in the body’s immune response) are collected from a person’s body, ‘armed’ with tumor-specific antigens – which will teach them to ‘hunt’ and destroy relevant cancer cells – and injected back into the body to boost the immune system.
Researchers in Switzerland identified a way to improve the action of these dendritic vaccines by creating artificial receptors able to recognise and ‘abduct’ tiny vesicles that have been linked to cancer tumour spread in the body.
By attaching these artificial receptors to the dendritic cells in the ‘vaccines,’ the therapeutic cells recognise harmful cancer cells with more accuracy.
IMMUNOTHERAPY + CHEMOTHERAPY
Recent studies have shown immunotherapy may work best if delivered in tandem with chemotherapy – specifically, if the chemotherapy drugs are delivered first, and then followed with immunotherapy.
This approach does have some pitfalls: it is difficult to control the e ects of this combined method; so sometimes healthy tissue may be attacked alongside cancer tumours.
However US scientists from two institutions in North Carolina have developed a substance that, once injected into the body, becomes gel-like: a ‘bioresponsive sca old system’. The sca old can hold both chemotherapy and immunotherapy drugs at once, releasing them systematically into primary tumours – hence allowing better control of both therapies, ensuring the drugs act on the targeted tumour alone.
NANOPARTICLES
The ‘boom’ in nanotechnology and nanoparticle developments has brought specially developed tools for delivering drugs straight to the tumor and hunting down micro tumors with accuracy and efficiency. Medicalnewstoday.com declared they could be ‘a game-changer’ in cancer treatment because ‘they bring us the chance to develop precise, less invasive methods of tackling disease’. Most importantly, they can target cancer cells or tumours without harming healthy cells in the surrounding environment.
Some nanoparticles have now been created to provide very focused hyper-thermic treatment – a type of therapy that uses hot temperatures to make cancer tumours shrink. In a major breakthrough, scientists from China and the UK developed a type of ‘self-regulating’ nanoparticle able to expose tumours to heat while avoiding contact with healthy tissue.
These tiny vehicles can also be used to target cancer stem-like cells, which are ‘undifferentiated cells that have been linked to the resilience of certain types of cancer in the face of traditional treatments such as chemotherapy’.
Thus nanoparticles can be ‘loaded’ with drugs and set to ‘hunt down’ cancer stem cells to prevent the growth or recurrence of tumours. For example, scientists have experimented with drug- lled nanoparticles in the treatment of various types of cancer, including breast cancer and endometrial cancer.
NANOPROBES
Equally importantly, minuscule vehicles called ‘nanoprobes’ can be used to detect the presence of micrometastases – secondary tumours so tiny they cannot be seen using traditional methods.
Dr Steven Libutti, director of the Rutgers Cancer Institute of New Jersey, calls micrometastases ‘the Achilles heel of surgical management for cancer’ and argues nanoprobes ‘go a long way to solving such problems.’
TUMOUR STARVATION
Another strategy researchers have been investigating is ‘starving’ tumors of the nutrients they need to grow and spread. Three different studies published in January 2018 looked at ‘ways of cutting o cancers’ nutritional supplies’.
One study looked at methods of stopping glutamine (a naturally occurring amino acid) from feeding cancer cells – breast, lung and colon cancers are known to use this amino acid to support their growth. By blocking cancer cells’ access to glutamine, the researchers maximised the impact of oxidative stress (a process that eventually induces cell death) on these cells.
In another study, researchers found some aggressive types of breast cancer may be halted by stopping the cells from ‘feeding’ on a particular enzyme that helps them produce the energy they need to thrive.
And UK researchers at the University of Salford found another way of depleting cancer cells of energy is by blocking their access to vitamin B-2.
All three studies suggest ‘the beginning of an alternative approach to halting cancer stem cells’ and a strategy that ‘could help individuals receiving cancer treatment avoid the toxic side e ects of chemotherapy’. AMP
Sources: Nature Immunology and medicalnewstoday.com
