Cytostatic drugs, that is, chemotherapy, can stop the spread of cancer cells or destroy them. However, although standard chemotherapy is toxic to tumor cells, it is also toxic to healthy cells.
Especially rapidly dividing cells, such as those of the bone marrow, hair roots and mucosal cells in the gastrointestinal tract, are affected by it, causing harmful side effects for patients: nausea, vomiting, sweating, tremors, fever, hair loss, loss of appetite, diarrhea, stomach pain, blood disorders, fatigue, high risk of infections and deterioration of different organs.
However, if the chemotherapy were aimed specifically at the tumor cells, the collateral effects of this aggressive anticancer therapy would be eliminated.
Now, an innovative therapy can direct chemotherapy drugs directly to the tumor cells of the female reproductive tract through a curious transport system: sperm.
The laboratory of Dr. Haifeng Xu, of the Leibniz Institute for Solid State Research and Materials, in Germany, has developed sperm with doxorubicin, a chemotherapy drug, and has spread it in a laboratory environment to tumor cells of cervical cancer. As a result, sperm killed 87% of the tumor cells in less than three days.
An advance that, although it has not yet been tested in humans, could mean a revolution in the treatment of cancer, increasing the life expectancy of patients undergoing treatment, and allowing much more effective targeting of anticancer treatment.
How can sperm recognize tumors?
The key to the revolutionary therapy lies in the ability of sperm to detect tumor cells. To achieve this, the German team equipped the sperm with small four-arm magnetic harnesses that allowed them to be guided by magnets. As described in the study, it is a micromotor driven by sperm.
When the sperm hit a solid tumor, the arms open, releasing the sperm and allowing them to swim towards the tumor. Once there, the drug is administered through the fusion of the tumor cell membrane with the sperm.
In general, sperm cells are excellent candidates to operate in physiological environments, since they do not express pathogenic proteins or proliferate to form undesirable colonies, unlike other cells or microorganisms.
According to the results obtained in the laboratory, the sperm cells exhibited a high capacity of drug encapsulation and drug-carrying stability, conveniently minimizing the toxic side effects and the undesired accumulation of drug in healthy tissues.
“In addition to cancer, sperm can be useful in treating other conditions that affect the female reproductive tract, such as endometriosis or ectopic pregnancies,” says study director Dr. Xu.
The shortcomings of chemotherapy
Chemotherapy, despite being one of the most used treatments against cancer, is also one of the most toxic, generating the need to try alternative therapies that reduce the damage in patients, such as immunotherapy, which combats tumor cells using the own human immunological functioning.
Cancer is a complex set of many diseases; therefore, the current trend of its treatment and eradication lies in the personalization of the therapies, and in directing the treatment to the tumor cells themselves, rather than to the body as a whole.