• Home  / 
  • Featured
  •  /  Scientists move a step closer to treating cancer-causing herpes

Scientists move a step closer to treating cancer-causing herpes

Kaposi's Sarcoma

Researchers have moved a step closer in developing a medication for an efficient treatment against a type of herpes which causes a form of cancer known as Kaposi’s sarcoma.

Before considering the new research, what is Kaposi’s sarcoma and how serious is it? Kaposi’s sarcoma is a tumor caused by human herpes virus 8. Kaposi’s sarcoma (KS) a systemic disease that can be present with cutaneous lesions (solitary, localized or disseminated). Four subtypes have been described: Classic KS, affecting middle aged men of Mediterranean descent; African endemic KS; KS in iatrogenically immunosuppressed patients; and AIDS-related KS.

With these different types:

  • Classic Kaposi sarcoma is most commonly appears early on the toes and soles as reddish, macules and patches that spread and coalesce The condition tends to affedt elderly men from the Mediterranean region, or of Eastern European descent.
  • Endemic KS has two types. Although this may be present worldwide, it has been originally described in young African people, mainly from sub-Saharan Africa.
  • Immunosuppression-associated Kaposi sarcoma primarily affects transplant patients. The tumor arises either when an HHV 8-infected organ is transplanted into someone who has not been exposed to the virus or when the transplant recipient already harbors pre-existing HHV 8 infection.
  • AIDS-associated Kaposi sarcoma typically presents with cutaneous lesions that begin as one or several red to purple-red macules, rapidly progressing to nodules and plaques, with a predilection for the head, back, neck, trunk, and mucous membranes. In more advanced cases, they can be found in the stomach and intestines, the lymph nodes, and the lungs.

The disease arises as a cancer of lymphatic endothelium and forms vascular channels that fill with blood cells, giving the tumor its characteristic bruise-like appearance. The tumor is highly vascular, containing abnormally dense and irregular blood vessels, which leak red blood cells into the surrounding tissue and give the tumor its dark color. Inflammation around the tumor may produce swelling and pain.

The disease is transmitted through different ways. It can be transmitted through saliva, which means that kissing is a risk factor for transmission. Higher rates of transmission among gay and bisexual men have been attributed to “deep kissing” infected sexual partners. Another possible means of transmission is through the use of saliva as a sexual lubricant. The disease is also transmissible via organ transplantation and blood transfusion.

In terms of detecting the disease, blood tests have been developed to detect antibodies against Kaposi’s sarcoma. These tests can be used to determine whether a patient is at risk for transmitting infection to their sexual partner, or whether an organ is infected prior to transplantation.

The new research, conducted by the University of Manchester (UK), has found that Herpes virus proteins are more ‘spaghetti-like’ than previously thought. This molecular-level finding provides a vital clue in developing a medication against the virus.

The science team have discovered that the virus protein uses its flexible arms to pass on viral building blocks to the proteins of cells that it hijacks. The research has also revealed that the protein of cells hijacked by the herpes virus take on a ‘spaghetti-like’ structure.

To show this the team used a technique similar to that used for MRI body scanners. The method is capable of visualising molecules at the smallest scales. This allowed the scientists to examine how small components of the herpes virus help it to multiply by binding themselves with other large molecules. The images that were produced were next used to develop a 3D model of how viral RNA is recognised by this herpes virus protein and then passed on to the cellular protein of the host

What is interesting about the research is that it provides the first ever molecular insight of how the herpes virus RNA (the molecule which helps to decode the generic blueprint of a virus) is transferred between viral and cellular proteins, thus helping the virus to hijack a cell (viruses cannot survive or replicate on their own, they need to use a host cell – in this case from the human body – to do so).

Currently there is no effective antiviral treatment currently available against human herpes virus 8, which can suppress the viral replication. Finding a weak spot in the virus, which can be used to prevent Kaposi’s sarcoma in the future, would make a significant breakthrough. The University of Manchester science team hope that their new discovery will be the starting point for the quest for a treatment.

The new research has been published in the journal PLoS Pathogens, in a research paper titled “Competitive and Cooperative Interactions Mediate RNA Transfer from Herpesvirus Saimiri ORF57 to the Mammalian Export Adaptor ALYREF”.

About the author

Tim Sandle

Dr. Tim Sandle is a chartered biologist and holds a first class honours degree in Applied Biology; a Masters degree in education; and has a doctorate from Keele University.