Fluorescence Microscopy Tumor Sample
Science & Technology

MIT Chemical Engineers Hunting a “Jekyll-and-Hyde” Molecule

Fluorescence microscopy picture of a tumor pattern the place elevated ranges of hydrogen peroxide have been found. Credit score: Picture courtesy of the researchers

A screening technique developed by MIT researchers targets hydrogen peroxide within the seek for new most cancers therapeutics.

MIT chemical engineers have developed a method of swiftly screening compounds to find out their therapeutic potential for sure sorts of cancers. With a genetically engineered sensor and high-throughput know-how, their technique probes for modifications in mobile concentrations of hydrogen peroxide (H2O2), a specialised molecule referred to as an oxidant.

“The regulatory pathways of some tumors depend upon elevated ranges of H2O2,” says Hadley Sikes, affiliate professor and Esther and Harold E. Edgerton Profession Improvement Professor within the Division of Chemical Engineering. “However additional will increase in concentrations of this oxidant can result in programmed cell dying.” Within the researchers’ screens of 600 small-molecule compounds, they had been capable of determine people who selectively boosted H2O2.

Different analysis efforts have used probes that reply indiscriminately to completely different sorts of oxidants, making it tough to find out exactly which compounds make the best affect on these specialised molecules. The MIT display screen is the primary to zero in on a single oxidant. This enabled the crew to characterize the mobile responses to potential medication and to show that a few of these compounds activated H2O2-mediated toxicity in inclined most cancers cell strains.

Yining Hao performs a microplate assay to find out protein concentrations. The concentrations of peroxiredoxins, a household of antioxidant proteins, decide the degrees of hydrogen peroxide inside cells. Credit score: Picture courtesy of the researchers

Their analysis seems in Cell Chemical Biology. Yining Hao SM ’18 and Troy F. Langford SM ’15 PhD ’18 are first co-authors. The opposite contributors are Solar Jin Moon, a graduate pupil in chemical engineering, Kristen A. Eller ’16, who labored on the venture whereas an undergraduate, and Sikes.

“Our work helps pave the best way for extremely focused, oxidant-based chemotherapeutics,” says Hao, who’s finishing her doctorate in chemical engineering. “These research transfer us in the proper route for successfully using medication to deal with completely different sufferers — the thought behind customized drugs,” provides Langford, now a biotechnology affiliate for Cowen, Inc.

Hydrogen peroxide belongs to a household of molecules referred to as reactive oxygen species (ROS), that are concerned in metabolizing oxygen. “They’re referred to as ‘Jekyll-and-Hyde’ molecules,” says Sikes. “They’re a part of all of the issues we have to dwell — taking oxygen from the air, lowering it to water, producing vitality for the cells — however uncontrolled concentrations of ROS for too lengthy can have adverse results, corresponding to interfering with the signaling pathways inside cells.”

When genetic mutations kick-start cancers, typically oxidants corresponding to hydrogen peroxide improve dramatically, throwing cell features out of substances. As ranges of hydrogen peroxide rise, most cancers cells unleash antioxidants to maintain them in examine. It’s a tough metabolic steadiness to keep up, and it’s this weak point that researchers hope to use as they search new most cancers therapies.

“The thought is, if we selectively increase hydrogen peroxide, these careworn most cancers cells will die first,” says Hao. “We’re searching for molecular vulnerabilities that may have a better affect on most cancers than on the wholesome tissues that encompass it,” provides Sikes.

Medication have emerged for the anti-cancer arsenal that purpose to behave on these hydrogen peroxide mechanisms, both by immediately elevating mobile ranges of the oxidant, or by undermining antioxidant methods. However they don’t uniformly ship. With out a sure-fire technique for detecting hydrogen peroxide in most cancers cells earlier than and after drug remedy, precision therapeutics stays out of attain.

The biosensor Langford and Sikes devised in 2018 addressed this drawback. It makes use of an enzyme referred to as peroxiredoxin-2, which might register modifications in hydrogen peroxide ranges. Langford engineered the sensor in order that when it reacts with hydrogen peroxide, it fluoresces.

“We wished to make use of this sensor in a sensible method, and we thought: ‘What higher method to try this than a high-throughput display screen, utilizing a library of anti-cancer compounds proper subsequent door on the Koch Institute for Integrative Most cancers Analysis?’” says Langford. “We took these small molecules from their assortment and systematically added each to most cancers cells that contained our sensor.”

Sikes made the deliberate determination to take compounds that had been “already FDA-approved and secure in people,” she says, together with some that had beforehand been investigated as anti-cancer medication. The query was which, if any, could possibly be efficient in elevating concentrations of hydrogen peroxide within the human most cancers cell strains the crew had assembled.

As they ran their screens, researchers seemed for the purple fluorescing of the probe that signaled a rise in hydrogen peroxide ranges after the medication interacted with the cells. There have been certainly such hits, however in knowledge evaluation, Hao discovered that “a lot of those indicators had been weirdly excessive, outdoors of the sensor’s vary.”

The researchers ran a second spherical, to verify the indicators truly mirrored hydrogen peroxide degree modifications. After working via the library of drug candidates, the researchers not solely pinpointed compounds that modulated hydrogen peroxide in particular most cancers cells, but in addition linked a few of these compounds to the dying of cells.

There have been surprises. One drug, SMER3, an antifungal, ramped up hydrogen peroxide ranges. “This was probably the most thrilling one we got here throughout,” says Sikes. “It kills yeast and it turned out to be efficient killing a subset of cancers.”

One other headline from their research: A significant anti-cancer drug with a fame for enhancing oxidant ranges was a bust of their display screen. “Cisplatin didn’t induce hydrogen peroxide,” says Sikes. “Possibly it induces different oxidants, however not this one which drives dying response pathways in a subset of cancers.”

Their work has already catalyzed new enterprises. Sikes is partnering with a Boston clinician who focuses on cancers identified to be susceptible to ROS defects, corresponding to colon most cancers. As a part of his dissertation analysis, Langford examined SMER3 on colon most cancers cells. “It kills sure cell strains very effectively,” Hao says, “and we’d like to know it higher, to study if it’s secure, and what cell pathways it targets precisely.”

Subsequent steps contain shifting on to animal fashions bearing patient-derived cancers, says Sikes, and ultimately on to affected person populations.

Past hydrogen peroxide, Sikes envisions taking on different molecules that fulfill essential features in cells, and which may additionally function potent anti-cancer targets. “There are reactive nitrogen and sulfur species which might be additionally possible equally necessary and worthy of exploration.”

Reference: “Screening compound libraries for H2O2-mediated most cancers therapeutics utilizing a peroxiredoxin-based sensor” by Yining Hao, Troy F. Langford, Solar Jin Moon, Kristen A. Eller and Hadley D. Sikes, 21 October 2021, Cell Chemical Biology.
DOI: 10.1016/j.chembiol.2021.09.003

Assist for this analysis got here from the Haas Household Fellowship in Chemical Engineering, the MIT Superior Undergraduate Analysis Alternatives Program, and the Esther and Harold E. Edgerton endowed professorship.

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