Day: August 7, 2021

How Cancer Cells Develop Resistance to Chemotherapy

Source: National Cancer Institute on Unsplash

Researchers have found some answers as to why cancer cells can develop resistance to the cytotoxic drugs used in chemotherapy.

“We haven’t understood very much about how this resistance to chemotherapy develops and even less about how the microenvironment in cancer can affect the process,” said Kaisa Lehti, a professor at the Norwegian University of Science and Technology’s (NTNU) Department of Biomedical Laboratory Science.

Lehti has led this study into how cancerous tissues develop resistance to a particular form of chemotherapy, the results of which appear in Nature Communications.

If ovarian cancer is picked up early, almost all patients survive the first five years, while chances of survival are much worse if detected later. Finding effective treatment is therefore very important.

Platinum chemotherapy is one of the standard treatments for ovarian cancer, but cancer cells often develop resistance to this particular treatment. The reason lies in how the platinum-based cytotoxin itself can change the cancer cells and their environment.

Cytotoxin influences cancer cells and their environment
Lehti summed up the process: “The cytotoxin can change the way the cancer cells send and perceive signals and can modify the microenvironment around the cells.”

This change allows the cancer cells to withstand the damage caused by the cytotoxin—and can thus survive the chemotherapeutic attack. The researchers have found this key to the puzzle in a layer of tissue that often surrounds cancer cells.

“A fibrotic network of proteins, known as the extracellular matrix or ECM, surrounds the cancer cells, particularly the most aggressive ones,” said Lehti.

The fibrotic tissue, with the ECM network around the cancer cells, is mainly produced by normal connective tissue cells. But the cancer cells and connective tissue cells in the network can alter this tissue themselves.

“Previously, we haven’t known how the communication between the cancer cells and the extracellular matrix is affected by, or even itself influences, the development of cancer and its response to chemotherapy,” said Prof Lehti.

But it is now known that chemical and mechanical signals in the surrounding ECM tissue help cancer develop its ability to spread and to resist treatment.

“Certain signals from the ECM can critically change the cancer cells’ resistance to platinum-based cytotoxic drugs,” Prof Lehti explained.

In this way, the cytotoxin itself helps change both the microenvironment around the cancer cells and the ability of the cancer cells to sense their environment, and so resist the cytotoxin. By understanding this process, better therapies can be developed.

Source: MedicalXpress

Western Cape Third Wave Peak Expected Anytime Now

Image by Quicknews

Western Cape premier Alan Winde said that the province is at the peak of its third wave of COVID infections.

“We are beginning to see the flattening of the curve at our peak as new case infections start to plateau again,” he said in a briefing on Thursday. “This happened after an initial plateau two weeks ago, and then a subsequent increase the week thereafter.

“This is largely explained by a disruption in testing caused by the taxi violence in the Cape Metro during that time.”

Winde supplied the following information:

The ‘R’ number is currently 1.1 and the test positivity rate is 41.5%. New hospital admissions are at 339 per day, with a slight downturn. Deaths have increased, with about 108 deaths per day and will be the last indicator to fall.

Winde said that provincial authorities are simultaneously monitoring the number of trauma admissions to hospitals to ensure that there is sufficient capacity in the province’s hospitals and that it can proactively identify any risks so that they can be addressed.
Senior CSIR researcher Ridhwaan Suliman, PhD, who was been analysing COVID data tweeted an update on Friday night, indicating that there was still no sign of the peak passing just yet:

https://twitter.com/rid1tweets/status/1423718531208785921

Source: BusinessTech

A Look Back at Mkhize’s Tenure as Health Minister

Image by Hush Naidoo from Unsplash
Image by Hush Naidoo from Unsplash

With Dr Joseph Phaahla being promoted from his position as Deputy Health Minister to replace the embattle, Dr Zweli Mkhize, Spotlight reviews Dr Mkhize’s tenure, writing that the very reason he was brought in to that post — to roll out National Health Insurance — would likely suffer a considerable setback as a result of his exit.

His appointment as South Africa’s Minister of Health in May 2019 came as a surprise for some. As one of the ANC’s top officials, the health portfolio seemed a meagre choice in the pre-COVID days.

However, Mkhize’s seniority signalled that health was being given high priority in the new administration. Theoretically, his greater political clout meant he would have a better chance of bringing much-needed reforms to provincial healthcare systems. Spotlight were also “cautiously hopeful that Mkhize’s firmer hand would help better organise and direct the National Health Department and the various national health entities.”

A string of procurement scandals during his time as KwaZulu-Natal’s Premier was cause for concern but was not direct evidence that he was corrupt.

The Digital Vibes scandal had the side effect of making Mkhize anathema to the very project he was originally brought in for, implementing National Health Insurance.

Even with Mkhize gone, the ANC will have a hard time convincing the public that we will not see more such looting once NHI is implemented. There has, after all, been little willingness from ANC members in Parliament to engage seriously with people’s concerns about the proposed NHI structure and governance arrangements set out in the NHI Bill.

Mkhize tackled COVID from a scientific standpoint, which is fortunate for the nation considering the anti-scientific stance of the former Minister of Health Dr Manto Tshabalala-Msimang. However, the decision not to use AstraZeneca vaccines remains contentious. Meanwhile, a purge of scientists, starting with Professor Glenda Gray, let Mkhize surround himself with allies, according to Spotlight.

However, entering the third wave with vaccinations lagging so far behind was a governance disaster possibly even worse than the Digital Vibes scandal.

From an outside perspective, the past two years have not seen great progress in the department, despite some competent individuals, with infighting, under-capacity and most seriously, poor management. The procurement department

Source: Spotlight