How does cancer do it? Cell scaling and shapes
H Human cells come in many sizes and shapes that often provide clues to a cell’s function. Immune cells called macrophages, for example, have long tentacles that reach out and consume bacteria, viruses, or other cells. Neurons spread out to better communicate and transmit information. The squamous cells that line the skin and organs are thin and flat, like fish scales. Doctors also use forms of the cells to help diagnose diseases, such as sickle cell anemia, which is abnormal red blood cells. When it comes to cancer, the size or shape of the cells can be critical to help diagnose the type and stage of the disease.
“In general, cancer cells have larger nuclei than normal cells,” says Fernando Yu. “This is mainly due to changes in the DNA that lead to the development of cancer. This change in DNA gives cells a characteristic called hyperchromia, which means that the cells appear darker than normal cells, and pleomorphism, that is, cells of different shapes and sizes. .”
“It’s not just the shape that matters, but the number of cells and the variety of shapes. In most high-grade III cancers, for example, you see large, round, square, triangular cells. You’re looking at a variety of shapes and sizes.” – Fernando U García, MD, Pathologist
differentiation of cancer cells
Dr. Garcia says this messy collection of mutated, deformed cells could allow pathologists to determine if a tissue sample is cancerous. “It’s not just the shape that matters, but the number of cells and the variety of shapes,” he says. “In most high-grade III cancers, for example, you see large, round, square, triangular cells. You’re looking at a variety of shapes and sizes.” Scientists are also studying what these cell shapes can tell you about possible genetic mutations in some types of cancer and whether the shapes can help predict how cancer will metastasize through the body.
The shape of the cell can also help determine the specific type of cancer. For example, the shape of the cells helps determine whether a patient’s lymphoma is Hodgkin’s or non-Hodgkin’s. Hodgkin lymphoma patients have enlarged binucleated cells called Reed-Sternberg cells, which are shaped like an owl’s eyes and are not found in patients with non-Hodgkin’s lymphoma. Brain tumors called glioblastomas are also known as astrocytomas because they start in star-shaped cells called astrocytes.
- Mycoplasma gallisepticum is believed to be the smallest cell in the world, measuring 0.0001 mm in size. By comparison, a grain of salt is about 5 millimeters across and causes respiratory distress in chickens.
- The largest cell, Caulerpa taxifolia, is found in aquatic algae and can reach 30 cm in length.
- The largest cell in humans is the egg, the human egg. The smallest human cell is the sperm.
- The longest cells in the human body are nerve cells.
In recent years, several clinical trials have examined whether cell shapes can help doctors predict the likelihood that cancer will metastasize or metastasize to distant organs. Using computer algorithms and digital image analysis, Dr. Garcia and a team of researchers from Drexel University determined whether some patients’ breast cancer had metastasized to the lymph nodes. “We can predict lymph node metastases simply by looking at the cells on a slide and running the digital image through an algorithm,” says Dr. Garcia. “We’re looking at the shape of the cells, their relationship to each other, and interactions with normal structures, among other factors.”
Scientists at Cancer Research UK are also studying whether cancer cell shapes are linked to genetic mutations. By studying melanoma cells in mice, the researchers were able to identify several genes that they believe may influence the shape of the cells. Among them is a gene called PTEN, which when turned off allows cancer cells to become round or oblong—ideal shapes to help them spread. Round cells travel more easily through the bloodstream; Elongated cells are better able to penetrate the bone marrow or invade organs.
Lead researcher Chris Bacall, PhD, says that knowing more about cell shapes and the genes involved in how shapes determine cancer cell behavior could eventually lead to new therapies. “Changing the shape of the cancer to make it less aggressive can be effective in combination with other treatments, giving them a better chance of working,” says Dr. Bacall.
Learn more about the difference between benign and malignant tumors.