As the first-of-its-kind platform, the Microbubble-assisted UltraSound-guided Immunotherapy of Cancer (MUSIC) approach employs nanocomplexes combined with microbubbles to effectively deliver cyclic guanosine monophosphate-adenosine monophosphate (cGAMP), an immunotransmitter involved in anticancer immunity, into antigen-presenting cells (APCs). Inside the APCs, the microbubbles release cGAMP to activate the GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway, which stimulates type I interferon responses that are essential for priming tumor-specific T cells.

In the preclinical study, the MUSIC strategy demonstrated a complete tumor eradication rate of 60% when administered as monotherapy in breast cancer models. When combined with an anti-PD-1 antibody, MUSIC significantly improved antitumor responses with minimal toxicity effects, including enhanced primary tumor control and decreased systemic disease progression. In addition, the combination therapy demonstrated superior survival benefit, with a 76% increase in median survival compared to either therapy alone.

“By investigating the mechanisms of action in producing a robust STING activation, we identified a new strategy to activate both the innate and adaptive antitumor immune responses,” said Wen Jiang, M.D., Ph.D., assistant professor of Radiation Oncology and the study’s co-senior author. “Our findings show that the MUSIC strategy is capable of paving the way toward novel image-guided strategies for targeted cancer immunotherapy.”

Immunotherapy has transformed cancer treatment, offering clinical benefits for patients with treatment-refractory metastatic cancers such as melanoma, non-small cell lung cancer and renal cell cancer. However, not all patients respond to immune checkpoint blockade. Therefore, developing a more effective immunotherapy strategy to benefit larger numbers of cancer patients with localized and metastatic disease remains an unmet clinical need.

“Although the majority of cancer immunotherapies have focused on boosting the adaptive branch of the body’s immune system, there has been a growing realization that both the innate and adaptive branches of the body’s immune system need to be engaged to generate optimal antitumoral immunity,” Jiang said. “This understanding has led to the development of new immunotherapies that target the regulators of innate immune systems, including the cGAS-STING pathway.”

Natural agonists, such as cyclic dinucleotides, activate the cGAS-STING pathway, but concerns over poor cytosolic entry, serum stability and systemic toxicity have been major limitations for clinical translation. To overcome these challenges, Jiang and his collaborators developed MUSIC as the first-ever image-guided cancer immunotherapy strategy that uses antibody targeting to activate STING in APCs through delivery of molecular drugs.

Because the microbubbles also serve as contrast agents for ultrasound, the researchers use ultrasound scanners to image the tumor and to precisely identify the location where the microbubbles have accumulated. After confirming the microbubbles are bound to the tumors, the researchers activate ultrasonic frequencies, which cause the microbubbles to oscillate and burst, creating transient pores in the cell membrane that allow nucleic acids to be transferred directly into the cell cytosol. This technique, called sonoporation, previously has been used on tumor cells, but the MUSIC platform is the first to bind nanocomplexes to microbubbles to deliver cGAMP immunotransmitters directly into APCs.

“The beauty of our platform is that ultrasound machines are already clinically available in many outpatient settings and microbubbles are FDA-approved contrast agents for ultrasound imaging,” Jiang said. “Therefore, we expect there is a very real opportunity to translate MUSIC into a clinic application to benefit cancer patients.”

The same concept and design principle behind the MUSIC platform’s microbubble technology could be readily translated to nanoscale systems for targeted systemic delivery and activation of innate immune sensors under image guidance for cancer immunotherapy applications, Jiang added.

“Our MUSIC platform is exciting because it provides a new framework for developing image-guided immunotherapy by using acoustically responsive biomaterials to enable efficient, targeted and robust immune activation to produce potent antitumor effects while minimizing systemic toxicity,” Jiang said. “The versatility of the MUSIC platform could potentially be applied to targeted delivery of other immune-stimulating agents, such as nucleotide-based vaccines, mRNAs and other gene therapies for multiple human diseases.”

The study was supported by grants from the Cancer Prevention and Research Institute of Texas (CPRIT), Department of Defense and the National Cancer Institute. The study’s co-corresponding author is Jacques Lux, Ph.D., assistant professor of Radiology at The University of Texas Southwestern Medical Center.

However, past research has uncovered associations between the two diseases. Women with diabetes, for example, have a 20 to 27 percent increased risk of developing breast cancer. Insulin resistance — a key characteristic of diabetes — has been associated with breast cancer incidence and poor survival. Population studies suggest diabetes risk begins to increase two years after a breast cancer diagnosis, and by 10 years post-diagnosis, the risk is 20 percent higher in breast cancer survivors than in age-matched women without breast cancer.

But these epidemiological linkages are not clear-cut or definitive, and some studies have found no associations at all. In a new paper, publishing May 30, 2022 in Nature Cell Biology, a research team led by scientists at University of California San Diego School of Medicine describe a possible biological mechanism connecting the two diseases, in which breast cancer suppresses the production of insulin, resulting in diabetes, and the impairment of blood sugar control promotes tumor growth.

“No disease is an island because no cell lives alone,” said corresponding study author Shizhen Emily Wang, PhD, professor of pathology at UC San Diego School of Medicine. “In this study, we describe how breast cancer cells impair the function of pancreatic islets to make them produce less insulin than needed, leading to higher blood glucose levels in breast cancer patients compared to females without cancer.”

Wang said the study was inspired by early work and guidance from Jerrold Olefsky, MD, professor of medicine and associate dean for scientific affairs in the Division of Endocrinology and Metabolism at UC San Diego School of Medicine. Olefsky is co-senior author of the study with Wang.

The culprit, according to Wang and Olefsky, are extracellular vesicles (EV) — hollow spheres secreted or shed by cells that transport DNA, RNA, proteins, fats and other materials between cells, a sort of cargo communication system.

In this case, the cancer cells were found to be secreting microRNA-122 into the vesicles. Wang said when vesicles reach the pancreas, they can enter the islet cells responsible for insulin production, dispense their miR-122 cargo and damage the islets’ critical function in maintaining a normal blood glucose level.

“Cancer cells have a sweet tooth,” Wang said. “They use more glucose than healthy cells in order to fuel tumor growth, and this has been the basis for PET scans in cancer detection. By increasing blood glucose that can be easily used by cancer cells, breast tumors make their own favorite food and, meanwhile, deprive this essential nutrient from normal cells.”

The research was conducted using mouse models, which found that slow-releasing insulin pellets or a glucose-lowering drug known as an SGLT2 inhibitor restored normal control of glucose in the presence of a breast tumor, which in turn suppressed the tumor’s growth.

“These findings support a greater need for diabetes screening and prevention among breast cancer patients and survivors,” said Wang, noting that an inhibitor of miR-122, developed by Regulus Therapeutics Inc. in San Diego, is currently in clinical trial as a potential treatment for chronic hepatitis C. It has been found to be effective in restoring normal insulin production and suppressing tumor growth in mouse models of breast cancer.

“These miR-122 inhibitors, which happen to be the first miRNA-based drugs to enter clinical trials, might have a new use in breast cancer therapy,” Wang said.

Co-authors include: Minghui Cao, Roi Isaac, Wei Yan, Xianhui Ruan, Li Jiang, Yuhao Wan, Jessica Wang, Christine Caron, Donald P. Pizzo, Xuxiang Liu, Andrew R. Chin, Miranda Y. Fong, Oluwole Fadare, Richard B. Schwab, Wei Ying and Jack D. Bui, all at UC San Diego; Dorothy D. Sears, Arizona State University; Steven Neben and Denis Drygin, Regulus Therapeutics, Inc., San Diego; Xiwei Wu, Joanne Mortimer, Yuan Yuan and Susan E. Yost, all at City of Hope, Duarte, CA; Ziting Gao, Kaizhu Guo and Wenwan Zhong, all at UC Riverside.

Does the smell of a warm cup of coffee help you start your day the right way? Or can you not stand the strong, heady stuff? According to new research, how quickly your brain processes the smell of your morning beverage might depend on whether you think that odor is pleasant or not.

A team at the University of Tokyo created a special device that can deliver 10 diverse odors in a way that is accurate and timely. The odors were administered to participants who rated their pleasantness while wearing noninvasive scalp-recorded electroencephalogram (EEG) caps, which record signals inside the brain. The team was then able to process the EEG data using machine learning-based computer analysis, to see when and where the range of odors was processed in the brain with high temporal resolution for the first time.

“We were surprised that we could detect signals from presented odors from very early EEG responses, as quickly as 100 milliseconds after odor onset, suggesting that representation of odor information in the brain occurs rapidly,” said doctoral student Mugihiko Kato from the Graduate School of Agricultural and Life Sciences at the University of Tokyo.

Detection of odor by the brain occurred before the odor was consciously perceived by the participant, which didn’t happen until several hundred milliseconds later. “Our study showed that different aspects of perception, in particular odor pleasantness, unpleasantness and quality, emerged through different spatial and temporal cortical processing,” said Kato.

“The representation of unpleasantness in the brain emerged earlier than pleasantness and perceived quality,” said Project Associate Professor Masako Okamoto, also from the Graduate School of Agricultural and Life Sciences. When unpleasant odors (such as rotten and rancid smells) were administered, participants’ brains could differentiate them from neutral or pleasant odors as early as 300 milliseconds after onset. However, representation of pleasant odors (such as floral and fruity smells) in the brain didn’t occur until 500 milliseconds onwards, around the same time as when the quality of the odor was also represented. From 600-850 milliseconds after odor onset, significant areas of the brain involved in emotional, semantic (language) and memory processing then became most involved.

The earlier perception of unpleasant odors may be an early warning system against potential dangers. “The way each sensory system recruits the central nervous system differs across the sensory modalities (smell, light, sound, taste, pressure and temperature). Elucidating when and where in the brain olfactory (smell) perception emerges helps us to understand how the olfactory system works,” said Okamoto. “We also feel that our study has broader methodological implications. For example, it was not known that scalp-recorded EEG would allow us to assess representation of odors from time periods as early as 100 milliseconds.”

This high temporal resolution imaging of how our brains process odors may be a stepping stone towards better understanding the mechanisms of neurodegenerative diseases in future, such as Parkinson’s and Alzheimer’s diseases, in which a dysfunction in the sense of smell is an early warning sign. The team is interested in exploring several further research avenues. “In our daily life, odors are perceived along with other sensory information like vision, and each sense influences the perception of the other,” said Kato. “Although we presented olfactory stimuli alone in the current study, we think that analyzing brain activity under more natural conditions, such as presenting odors with a movie, is important.” Perhaps Smell-O-Vision might yet make a comeback?

Funding

This work was supported by the Grant-in-Aid for Scientific Research on Innovative Areas from Japan Society for the Promotion of Science to M.O. (18H04998 and 21H05808) and JST-Mirai program to K.T. (JPMJMI17DC and JPMJMI19D1).

Story Source:

Materials provided by University of Tokyo. Note: Content may be edited for style and length.

Cells are stressed by factors that may damage them, such as extreme temperatures, toxic substances, or mechanical shocks. When this happens, they undergo a range of molecular changes called the cellular stress response.

“Every cell, no matter from which organism, is always exposed to harmful substances in their environment that they have to deal with all the time,” said Gustavo Silva, assistant professor of biology at Duke and senior author on the paper. “Many human diseases are caused by cells not being able to cope with these aggressions.”

During the stress response, cells press pause the genes related to their normal housekeeping activities, and turn on genes related to crisis mode. Just like in a house being flooded, they put down the window cleaner, turn off the TV, and run to close the windows, then they patch holes, turn on the sump pump, and if needed, rip up carpet and throw away irreparably damaged furniture.

While studying mechanisms related to the cells’ health and their response to stress, the team saw that, under stress, a group of proteins was being modified inside the cells. They dug into it and found that the master regulator of this process is a gene called Rad6.

“When there is a stressor, cells need to change what proteins are produced,” said Vanessa Simões, associate in research in the Silva lab and lead author of the paper. “Rad6 goes in and gets the (protein-building) ribosomes to change their program and adapt what they are producing for the new stressful circumstances.”

Rad6 isn’t just any random gene. It can be found, sometimes under a different name, in almost all multicellular organisms. In humans, it is known for its association with a set of symptoms called “Nascimento Syndrome,” that include severe learning disabilities.

Nascimento Syndrome, also called X-linked intellectual disability type Nascimento, is still a poorly understood disease. It was officially described in 2006, and tends to run in families, giving scientists an early clue to its genetic causes. Affected individuals have severe learning disabilities, characteristic facial traits, with wide-set eyes and a depressed nose bridge, and a range of other debilitating symptoms.

Like many other genes, Rad6 doesn’t just do one thing. It’s a multiuse tool. By discovering an additional function, and one so tightly related to the cell’s health, Silva and his team get to add a new piece to the puzzle of Nascimento Syndrome.

“It’s still a big question or how exactly can a mutation to this gene lead to such a drastic syndrome in humans,” said Silva. “Our findings are exciting because Rad6 can be a model on which we can do genetic manipulations to try to understand how problems in coping with harmful conditions can be connected to how this disease progresses.”

“If we get a better understanding of how this gene works, we can actually try to interfere with it to help these patients have a better outcome.” he said.

But how does one actually “look” at what is happening with an infinitesimally small protein when a cell is stressed? With a fair amount of teamwork. Simões and Silva paired up with researchers from the Duke Biochemistry department and the Pratt School of engineering to gather all the help they needed.

“We used biochemistry analyses, cellular assays, proteomics, molecular modeling, cryo-electron microscopy, a whole set of advanced techniques,” said Silva.

“It’s the cool thing about being in a place like Duke,” he said. “We found collaborators and resources easily, right here, and that really increases the impact of a study and our ability to do a more complete work.”

Funding for this study was provided by US National Institutes of Health R00 Award ES025835 and R35 Award GM137954 to Gustavo Silva. This work was also supported in part by R01 Award GM141223 to Alberto Bartesaghi and the Intramural Research Program of the NIH, National Institute of Environmental Health Sciences Grant ZIC ES103326 to Mario J. Borgnia. Cryo- EM work was performed at the Duke University Shared Materials Instrumentation Facility (SMIF), a member of the North Carolina Research Triangle Nanotechnology Network (RTNN), which is supported by the National Science Foundation (grant ECCS- 1542015) as part of the National Nanotechnology Coordinated Infrastructure (NNCI). Funding was also provided from the UNC Lineberger Comprehensive Cancer Center through the University of California, Riverside Fund and the Cancer Center Support Grant P30CA016086.