Stories about: cancer research

Super suppressor: Boosting a gene that stifles tumor growth

Researchers have packaged a tumor suppressor into a therapeutic nanoparticle.
Researchers have packaged a tumor suppressor into a therapeutic nanoparticle. IMAGE: ISLAM, ET AL.

Most of the time, cancer cells do a combination of two things: they overexpress genes that drive tumor growth and they lose normal genes that typically suppress tumors. No two tumors are exactly alike, but some combination of these two effects is usually what results in cancer. Now, for the first time, researchers have shown that it’s possible to treat cancer by delivering a gene that naturally suppresses tumors.

Researchers from Boston Children’s Hospital, Brigham and Women’s Hospital and Memorial Sloan Kettering Cancer Center combined their cancer biology and nanomaterials expertise and developed a therapeutic capable of delivering a tumor suppressor gene known as PTEN, the loss of which can allow tumors to grow unchecked.

In several preclinical models, their PTENboosting therapeutic was able to inhibit tumor growth. Their findings were published yesterday in Nature Biomedical Engineering.

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Cancer researchers hit a bullseye with a new drug target for Ewing sarcoma

Cell staining shows the lethal efficacy of CDK+PARP inhibitors against Ewing sarcoma
Fluorescent staining shows how PARP and CDK12 inhibitors combine to deal a lethal blow to Ewing sarcoma. In the top row, green represents locations of DNA damage incurred by Ewing sarcoma cells. In the bottom row, red represents DNA repair activity. Together, PARP and CDK12 inhibitors lead to Ewing sarcoma cell death.

Screening a class of recently-developed drug compounds — so-called “CDK inhibitors” capable of blocking CDK7/12/13 proteins — against hundreds of different human cancer cell lines, researchers at Dana-Farber/Boston Children’s Cancer and Blood Disorders Center have found that CDK12 inhibitors pack a particularly lethal punch to Ewing sarcoma, a rare cancer typically affecting children and young adults.

“No one has previously considered CDK12 inhibition as a way to combat Ewing sarcoma,” says Kimberly Stegmaier, MD, senior author of the new Cancer Cell paper that describes the findings.

In 2014, Nathaneal Gray, PhD, co-author on the new paper, and his team were the first to develop CDK inhibitors.

Some individuals were entirely cured of the disease

“Now, in mice, we’ve shown that Ewing sarcoma cells die if CDK12 is knocked out genetically or chemically inhibited,” Stegmaier says. What’s more, her team has discovered that CDK12 inhibition can be combined with another drug, called a PARP inhibitor, to double down on Ewing sarcoma cells.

The revelation that CDK12 inhibition can kill Ewing sarcoma cells brings a surge of hope to the field of pediatric oncology, which has long been challenged to find new drugs against childhood cancers.

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Dulling cancer therapy’s double-edged sword: A new way to block tumor recurrence

An immune cell engulfs cancer cells
An immune cell engulfs tumor cells.

Researchers have discovered that killing cancer cells can actually have the unintended effect of fueling the proliferation of residual, living cancer cells, ultimately leading to aggressive tumor progression.

The findings of the multi-institutional research team — including scientists from the Dana-Farber/Boston Children’s Cancer and Blood Disorders Center, Beth Israel Deaconness Medical Center and the Institute for Systems Biology — contradict the conventional approach to treating cancer.

In their study, published in the January issue of the Journal of Experimental Medicine, the researchers describe how chemotherapy or other targeted therapies create a build-up of tumor cell debris, comprised of dead, fragmented cancer cells. In animal models, the team observed that this cell debris sets off an inflammatory cascade in the body and also encourages lingering, living cancer cells to develop into new tumors.

“Our findings reveal that conventional cancer therapy is essentially a double-edged sword,” says co-senior author on the study Mark Kieran, MD, PhD, who directs the Pediatric Brain Tumor Program at Dana-Farber/Boston Children’s and is an associate professor of pediatrics at Harvard Medical School. “But more importantly, we also found a pathway to block the tumor-stimulating effects of cancer cell debris — using a class of mediators called resolvins.”

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