Breaking News
February 22, 2019 - Growing number of cancer survivors, fewer providers point to challenge in meeting care needs
February 22, 2019 - Innovative compound offers a new therapeutic approach to treat multiple sclerosis
February 22, 2019 - $1.5 million grant to develop opioid treatment program for jail detainees
February 22, 2019 - FDA’s new proposed rule would update regulatory requirements for sunscreen products in the U.S
February 22, 2019 - Most Hip, Knee Replacements Last Decades, Study Finds
February 22, 2019 - Wellness problems prevalent among ob-gyn residents
February 22, 2019 - In the Spotlight: “The world is your oyster in geriatrics”
February 22, 2019 - Successful testing of multi-organ “human-on-a-chip” could replace animals as test subjects
February 22, 2019 - Analysis of cervical precancer shows decline in two strains of HPV
February 22, 2019 - Sugary stent eases suturing of blood vessels
February 22, 2019 - From surgery to psychiatry: A medical student reevaluates his motivations
February 22, 2019 - Is New App From Feds Your Answer To Navigating Medicare Coverage? Yes And No
February 22, 2019 - New pacemakers powered by heartbeats could reduce need for surgery
February 22, 2019 - The United States records highest drug overdose death rates
February 22, 2019 - Phase 1 data reinforce safety profile of new drug for treating Duchenne muscular dystrophy
February 22, 2019 - Vitamin D supplementation less effective in the presence of obesity, shows study
February 22, 2019 - Sarepta Announces FDA Acceptance of Golodirsen (SRP-4053) New Drug Application for Patients with Duchenne Muscular Dystrophy Amenable to Skipping Exon 53
February 22, 2019 - An institutional effort to reduce the amount of opioids prescribed following lumbar surgery
February 22, 2019 - Failure to take statins leads to higher mortality rates | News Center
February 22, 2019 - New study explains why some patients report phantom sensations after limb amputation
February 22, 2019 - First motor-controlled heart valves implanted by Mainz University Medical Center
February 22, 2019 - Novel preclinical model mimics persistent interneuron loss seen in preterm infants
February 22, 2019 - Global health burden of glaucoma has increased, study reveals
February 22, 2019 - A holistic approach key to minimize treatment complexity in patients with interstitial lung disease
February 22, 2019 - 1 in 10 middle-aged Chinese adults are at high risk for heart disease, finds study
February 22, 2019 - More than half a million breast cancer patient’s lives saved by improvements in treatment
February 22, 2019 - Study finds no evidence that tougher policies prevent teenage cannabis use
February 22, 2019 - New blood test detects genetic disorders in fetuses
February 22, 2019 - Lower Self-Perception Observed in Children With Amblyopia
February 22, 2019 - Up to 15 percent of children have sleep apnea, yet 90 percent go undiagnosed
February 22, 2019 - Rare pulmonary defect prompts parents’ nationwide search for answers | News Center
February 22, 2019 - Lesbian and bisexual women at greater risk of being overweight, study finds
February 22, 2019 - UQ research may explain why vitamin D is essential for brain health
February 22, 2019 - Heart Attacks Rising Among Younger Women
February 22, 2019 - How your smartphone is affecting your relationship
February 22, 2019 - Orthopaedic surgeon receives prestigious award, $10 million grant | News Center
February 22, 2019 - New sepsis test could save thousands of lives
February 22, 2019 - Cervical cancer could be eradicated by 2100
February 21, 2019 - Sustained smoking cessation can lower risk of seropositive RA
February 21, 2019 - Thousands with chronic UTIs are not receiving the treatment they need
February 21, 2019 - Are teens getting high on social media? The surprising study seeking the pot-Instagram link
February 21, 2019 - Stanford expands biobank services | News Center
February 21, 2019 - Scientists identify link between drinking contexts and early onset intoxication among adolescents
February 21, 2019 - Strong social support may reduce cardiovascular disease risk in postmenopausal women
February 21, 2019 - Rapid expansion of interventions could prevent up to 13 million cases of cervical cancer within 50 years
February 21, 2019 - Motif Bio Receives Complete Response Letter From The FDA
February 21, 2019 - Researchers map previously unknown disease in children
February 21, 2019 - A skeptical look at popular diets: Going gluten-free
February 21, 2019 - Podcast: KHN’s ‘What The Health?’ How Safe Are Your Supplements?
February 21, 2019 - Factors associated with increased risk of developing surgical site infections
February 21, 2019 - Anticipatory signals in eye movements can help measure attentive capacity, learning with greater precision
February 21, 2019 - Study explores daily exposure to indoor air pollutants
February 21, 2019 - Evening exercise does not negatively affect sleep, may also reduce hunger
February 21, 2019 - Artificial intelligence technique can be used to identify alcohol misuse in trauma setting
February 21, 2019 - Overweight, obesity in adolescence associated with increased risk of renal cancer later in life
February 21, 2019 - BGU develops new AI platform for monitoring and predicting ALS progression
February 21, 2019 - Researchers discover a new promising target to improve HIV vaccines
February 21, 2019 - Brief Anesthesia in Infancy Does Not Mar Neurodevelopment
February 21, 2019 - Gaming system helps with autism diagnosis
February 21, 2019 - Heart Disease: Six Things Women Should Know
February 21, 2019 - More States Say Doctors Must Offer Overdose Reversal Drug Along With Opioids
February 21, 2019 - Researchers explore case studies focused on industries that kill more people than employed
February 21, 2019 - Only half of GP practice buildings are fit for purpose
February 21, 2019 - Intense exercise, fasting and hormones can enhance waste-protein removal, study shows
February 21, 2019 - Scientists can monitor brain activity to predict epileptic seizures few minutes in advance
February 21, 2019 - Study quantifies hepatic and intestinal mRNA expression of Ugt isoforms in rats
February 21, 2019 - ‘Apple-Shaped’ Body? ‘Pear-Shaped’? Your Genes May Tell
February 21, 2019 - Can we repair the brain? The promise of stem cell technologies for treating Parkinson’s disease
February 21, 2019 - Trump Plan To Beat HIV Hits Rough Road In Rural America
February 21, 2019 - PENTAX Medical introduces new electrosurgical and argon plasma coagulation platforms
February 21, 2019 - Trump plan to beat HIV hits rough road in rural America
February 21, 2019 - Eating blueberries every day could help decrease blood pressure
February 21, 2019 - ‘No Second Chances’ report calls for new measures to combat cardiovascular disease in Australia
February 21, 2019 - Mayo clinic researchers discuss local case studies of leprosy
February 21, 2019 - Scientists demonstrate key role of salt in allergic immune reactions
February 21, 2019 - Experts propose revising the criteria for diagnosis of Parkinson’s disease
February 21, 2019 - The med student and the machine
February 21, 2019 - Hey, Hey! Ho, Ho! Is Striking For School Nurses The Way To Go?
February 21, 2019 - Latest research encourages children to move out and learn through physical activity
February 21, 2019 - Proper oral hygiene and regular visits to dentist can promote heart health
New sensor allows scientists to measure cancer cell’s response to chemotherapy drug

New sensor allows scientists to measure cancer cell’s response to chemotherapy drug

image_pdfDownload PDFimage_print

MIT chemical engineers have developed a new sensor that lets them see inside cancer cells and determine whether the cells are responding to a particular type of chemotherapy drug.

The sensors, which detect hydrogen peroxide inside human cells, could help researchers identify new cancer drugs that boost levels of hydrogen peroxide, which induces programmed cell death. The sensors could also be adapted to screen individual patients’ tumors to predict whether such drugs would be effective against them.

“The same therapy isn’t going to work against all tumors,” says Hadley Sikes, an associate professor of chemical engineering at MIT. “Currently there’s a real dearth of quantitative, chemically specific tools to be able to measure the changes that occur in tumor cells versus normal cells in response to drug treatment.”

Sikes is the senior author of the study, which appears in the Aug. 7 issue of Nature Communications. The paper’s first author is graduate student Troy Langford; other authors are former graduate students Beijing Huang and Joseph Lim and graduate student Sun Jin Moon.

Tracking hydrogen peroxide

Cancer cells often have mutations that cause their metabolism to go awry and produce abnormally high fluxes of hydrogen peroxide. When too much of the molecule is produced, it can damage cells, so cancer cells become highly dependent on antioxidant systems that remove hydrogen peroxide from cells.

Drugs that target this vulnerability, which are known as “redox drugs,” can work by either disabling the antioxidant systems or further boosting production of hydrogen peroxide. Many such drugs have entered clinical trials, with mixed results.

“One of the problems is that the clinical trials usually find that they work for some patients and they don’t work for other patients,” Sikes says. “We really need tools to be able to do more well-designed trials where we figure out which patients are going to respond to this approach and which aren’t, so more of these drugs can be approved.”

To help move toward that goal, Sikes set out to design a sensor that could sensitively detect hydrogen peroxide inside human cells, allowing scientists to measure a cell’s response to such drugs.

Existing hydrogen peroxide sensors are based on proteins called transcription factors, taken from microbes and engineered to fluoresce when they react with hydrogen peroxide. Sikes and her colleagues tried to use these in human cells but found that they were not sensitive in the range of hydrogen peroxide they were trying to detect, which led them to seek human proteins that could perform the task.

Through studies of the network of human proteins that become oxidized with increasing hydrogen peroxide, the researchers identified an enzyme called peroxiredoxin that dominates most human cells’ reactions with the molecule. One of this enzyme’s many functions is sensing changes in hydrogen peroxide levels.

Langford then modified the protein by adding two fluorescent molecules to it — a green fluorescent protein at one end and a red fluorescent protein at the other end. When the sensor reacts with hydrogen peroxide, its shape changes, bringing the two fluorescent proteins closer together. The researchers can detect whether this shift has occurred by shining green light onto the cells: If no hydrogen peroxide has been detected, the glow remains green; if hydrogen peroxide is present, the sensor glows red instead.

Predicting success

The researchers tested their new sensor in two types of human cancer cells: one set that they knew was susceptible to a redox drug called piperlongumine, and another that they knew was not susceptible. The sensor revealed that hydrogen peroxide levels were unchanged in the resistant cells but went up in the susceptible cells, as the researchers expected.

Sikes envisions two major uses for this sensor. One is to screen libraries of existing drugs, or compounds that could potentially be used as drugs, to determine if they have the desired effect of increasing hydrogen peroxide concentration in cancer cells. Another potential use is to screen patients before they receive such drugs, to see if the drugs will be successful against each patient’s tumor. Sikes is now pursuing both of these approaches.

“You have to know which cancer drugs work in this way, and then which tumors are going to respond,” she says. “Those are two separate but related problems that both need to be solved for this approach to have practical impact in the clinic.”

Source:

http://news.mit.edu/2018/sensor-could-help-doctors-select-effective-cancer-therapy-0807

Tagged with:

About author

Related Articles