Weizmann’s cancer research world first

(TIMES OF ISRAEL) Researchers at the Weizmann Institute of Science have discovered, in a world first, that specialised immune cells known as memory B cells can recognise and attack ovarian cancer tumours.

Ovarian cancer is the deadliest gynaecological cancer worldwide, with a five-year survival rate below 50 per cent.

The peer-reviewed study, conducted in Professor Ziv Shulman’s lab in Weizmann’s Department of Systems Immunology, challenges the scientific assumption that immune memory B cells only respond to external invaders such as viruses and bacteria.

The research, led by Dr Nachum Nathan, appeared in Immunity. It identified memory cells that zeroed in on ovarian tumours and produced effective antibodies against them.

The findings pave the way for the development of vaccines and therapies that harness immune memory to fight cancer.

“If we suggest that there are memory cells, antibody-forming cells that remember the tumour, and we can activate them with a vaccine, then we can make cancer vaccines that stimulate these cells,” said Shulman, who supervised the research. “I’m very excited. It’s a new idea, a totally new approach to vaccines for cancer patients.”

Shulman said he went into cancer research from the field of “studying the B cell and antibody side, rather than from the cancer side”.

He started studying the role of B cells fighting cancer in 2015 on a hunch.

“We found that B cells infiltrate tumours and produce antibodies against cancerous ovarian tumours,” Shulman said.

In the most recent study, the research team analysed samples collected from 11 patients with the most common type of ovarian cancer, HGSOC, in collaboration with Professor Ram Eitan and Dr Oded Raban from Rabin Medical Centre.

They looked for B cells in the lymph node and tumour of the same patient.

“Each cell has its own unique antibody with its own sequence. It’s like a barcode,” Shulman said. “We found the same barcode in both the lymph node and the tumour.”

This provides “very strong evidence” that memory cells can move from the lymph node to the tumour, secreting antibodies that can be beneficial to the patient, he said.

The researchers produced the antibodies artificially in the lab.

“We were amazed to find that more than a third of these antibodies bound strongly to ovarian cancer cells,” Shulman said. “The memory cells can be a targeted weapon against ovarian cancer.”

Shulman said that he hopes the next step will be clinical trials for a B lymphocyte vaccine.

“This puts a new therapeutic option out there for people to use in clinical trials,” he said.