Posts Tagged ‘development’

New blood test could offer more tailored treatment of ovarian cancer

Researchers from The University of Manchester and The Christie NHS Foundation Trust — both part of Manchester Cancer Research Centre — say the test could be developed and used in hospitals within the next few years.

It would mean medics could see which patients could benefit from blood vessel-targeting drugs — such as bevacizumab — in addition to conventional therapy. Meanwhilehile others who are not going to benefit would be spared the time and side effects associated with having the drug.

The test would also help to reduce the cost to the NHS. Ovarian cancer has seen little increase in survival rates over the last few decades and scientists are seeking new treatment strategies to improve the standard approach of surgery and chemotherapy.

A recent advance has been to target the development of new blood vessels within the tumor — preventing the cancer from receiving the nutrients it needs to grow. Bevacizumab, one of the blood vessel-targeting drugs, has shown significant but modest improvements in patient survival so doctors are seeking ways to predict which patients are most likely to gain an advantage from this type of drug.

The research team looked at blood samples from patients enrolled in an international trial of bevacizumab. These patients received either standard chemotherapy treatment alone or chemotherapy plus the blood vessel-targeting drug.

Professor Gordon Jayson, Professor of Medical Oncology at The University of Manchester and Honorary Consultant at The Christie who jointly led the study, said: “We are keen to identify predictive biomarkers — measures that can indicate how well a patient will respond to treatment — so we can better target these drugs to patients most likely to benefit.”We investigated levels of a range of proteins in patients’ pre-treatment blood samples to see if any were associated with improved survival.”

The findings, published recently in the journal Clinical Cancer Research, show that two particular proteins — Ang1 and Tie2 — could be used in combination to predict patient response. Patients with high levels of Ang1 and low levels of Tie2 were most likely to benefit from bevacizumab.

Both these proteins are involved in controlling the formation of new blood vessels. Conversely, they found that patients with high levels of both proteins did not benefit from the additional drug.

Study co-author Professor Caroline Dive, from the Cancer Research UK Manchester Institute based at The University of Manchester, added: “We will now look to further explore the potential of using a blood test to personalise treatment for ovarian cancer patients.

Moving towards a more individualized treatment plan specific for each patient and their particular tumor is key to improving outcomes for patients while sparing those unlikely to benefit from potential side effects of therapy.”

source : http://www.sciencedaily.com/releases/2014/09/140905090419.htm

Understanding, improving body’s fight against pathogens

While they exist in small populations in humans, the large amounts of antibodies secreted by plasma cells make them key to the body’s immune system and its ability to defend itself against pathogens, such as bacteria and viruses. Proper maintenance of a pool of plasma cells is also critical for the establishment of lifelong immunity elicited by vaccination.

Dysregulation of plasma cell production and maintenance could lead to autoimmune diseases and multiple myeloma. Autoimmune diseases occur when the immune system does not distinguish between healthy tissue and antigens, which are found in pathogens. This results in expansion of plasma cells which produce excessive amounts of antibodies leading to destruction of one’s own healthy tissue. The discoveries by scientists in BTI’s Immunology Group have improved understanding of the mechanism by which plasma cells are developed from a major class of white blood cells called B cells.

For the first time, the molecule DOK3 was found to play an important role in formation of plasma cells. While calcium signalling typically controls a wide range of cellular processes that allow cells to adapt to changing environments, it was found to inhibit the expression of the membrane proteins essential for plasma cell formation. These membrane proteins include PDL1 and PDL2, and represent some of the key targets for the development of immunotherapy by pharmaceutical companies. DOK3 was able to promote the production of plasma cells by reducing the effects of calcium signalling on these membrane proteins. The absence of DOK3 would thus result in defective plasma cell formation.

In another study, BTI scientists discovered the importance of SHP1 signalling to the long term survival of plasma cells. While the molecule SHP1 has a proven role in prevention of autoimmune diseases, it was found that the absence of SHP1 would result in the failure of plasma cells to migrate from the spleen where they are generated to the bone marrow, a survival niche where they are able to survive for much longer periods. This could result in a reduction of the body’s immune response and thus, an increased susceptibility to infections and diseases. The scientists in this study also successfully rectified the defective immune response caused by an absence of SHP1 by applying antibody injections, which might advance the development of therapeutics. On the other hand, targeting SHP1 might be a strategy to treat multiple myeloma where the accumulation of cancerous plasma cells in the bone marrow survival niches is undesirable.

Findings hold potential for improved treatment

The discovery of these new targets for modulating the antibody response allows the development of novel therapeutic strategies for patients with autoimmune diseases and cancer.Understanding the mechanism that governs plasma cell differentiation is also critical for the optimal design of vaccines and adjuvants, which are added to vaccines to boost the body’s immune response.

Prof Lam Kong Peng, Executive Director of BTI, said, “These findings allow better understanding of plasma cells and their role in the immune system. The identification of these targets not only paves the way for development of therapeutics for those with autoimmune diseases and multiple myeloma, but also impacts the development of immunological agents for combating infections.”

source : http://www.sciencedaily.com/releases/2014/09/140902115036.htm

Finding keys to glioblastoma therapeutic resistance

“There is a growing interest to guide cancer therapy by sequencing the DNA of the cancer cell,” said Clark Chen, MD, PhD, vice-chairman of Research and Academic Development, UC San Diego Division of Neurosurgery and the principal investigator of the study. “Our study demonstrates that the sensitivity of glioblastoma to a drug is influenced not only by the content of its DNA sequences, but also by how the DNA sequences are organized and interpreted by the cell.”

The team of scientists, led by Chen, used a method called comparative gene signature analysis to study the genetic profiles of tumor specimens collected from approximately 900 glioblastoma patients. The method allows investigators to discriminate whether specific cellular processes are “turned on” or “turned off” in glioblastomas. “Our study showed that not all glioblastomas are the same. We were able to classify glioblastomas based on the type of cellular processes that the cancer cells used to drive tumor growth,” said Jie Li, PhD, senior postdoctoral researcher in the Center for Theoretical and Applied Neuro-Oncology at UC San Diego and co-first author of the paper.

One of these cellular processes involves Epidermal Growth Factor Receptor (EGFR). The study revealed that EGFR signaling is suppressed in a subset of glioblastomas. Importantly, this suppression is not the result of altered DNA sequences or mutations. Instead, EGFR is turned off as a result of how the DNA encoding the EGFR gene is organized in the cancer cell. This form of regulation is termed “epigenetic.” Because EGFR is turned off in these glioblastomas, they become insensitive to drugs designed to inhibit EGFR signaling.

“Our research suggests that the selection of appropriate therapies for our brain tumor patients will require a meaningful synthesis of genetic and epigenetic information derived from the cancer cell,” said co-first author Zachary J. Taich.

The paper’s abstract can be found at: http://www.impactjournals.com/oncotarget/index.php?journal=oncotarget&page=article&op=view&path[]=2350

source : http://www.sciencedaily.com/releases/2014/08/140825185321.htm