Discover new mechanisms of breast cancer recurrence

For many patients who think they have overcome breast cancer, recurrence of breast cancer after a period of time is a particularly cruel thing, and currently researchers do not have a clear answer for the cause and mechanism of breast cancer recurrence. Now, a team at the university of California's cancer institute has revealed some unknown mechanisms, and the new findings could lead to new drugs to further address the problem of breast cancer recurrence.
In mice, the researchers tracked a series of events that allowed a small percentage of treatment-resistant cancer cells to wake up, grow and spread from hibernation. "These are cancer cells left over from treatment, and we know very little about them because we can't see them." "Their Numbers are too small to be shown on mammography or PET scans," said Dr. James v. Alvarez, an assistant professor in the department of pharmacology and cancer biology at the university of California. But with a mouse model of recurrent her2-positive breast cancer, we were able to find cancer remnants that survived treatment and study them.

Alvarez and his colleagues found that the remaining, hard-to-kill tumor cells did not grow and multiply as rapidly as the original cancer cells. Instead, they lurk and begin complex interactions with surrounding cells, especially those of the immune system. Over time, they will activate small signaling proteins known as cytokines, cell factor is an important way of communication, the immune cells through the role of cytokines, immune cell can quickly reach the tumor site, including macrophages is the response of immune cells in the largest number of a, it is a kind of white blood cells, can digest cellular debris and secrete a collagen deposition, the collagen is very important for dormancy revival and growth of cancer cells.

When Alvar......

Preparing Animal Cell Slide and Microscopic Measurement

2.1 Objectives
(1) Learn to prepare blood smear slide and observe blood cells under optical microscope.
(2) Learn to prepare human oral epithelial cell slide and observe epithelial cells under optical microscope.
(3) Learn to measure the cell size by the use of graticules under optical mieroscope.
2.2 Introductions
The technique of preparing blood cell smear slide is generally used for morphologic observation, cellular classification and cell number counting in clinic diagnosis of diseases and physical examination.
2.3 Principles
Different cells have their special morphology structures and functions. In animal blood, there are erythrocytes, also called red blood cells, and leukocytes, also called white blood cells. Mature human red blood cells are oval biconcave disks without cell nuclei and most organelles, but amphibian's red blood cells still keep their nuclei. Human white blood cell sinclude monocytes, neutrophils, eosinophils, basophils and lymphocytes. Monocytes have abundant cytoplasm and kidney shaped nuclei. which are typically granulated. Once they move out the bloodstream, they become tissue macrophages. Neutrophils constitute 60%-70% of the circulating white blood cell with a distinctive feature of multi-lobed nuclei, which consists of three to five lobes connected by slender strands. Eosinophils compose about 2%-4% of the circulating white blood cell with bi-lobed nuclei. Basophils are less than 0. 5% of the circulating white blood cell with bi- or tri- lobed nuclei. They are characterized by several coarse, dark violet granules. Lymphocytes have a relatively small amount of cytoplasm and deeply staining nuclei. Hemocytometer is used to count cell numbers in a specific volume of fluid under microscope. lt consists of a thick glass microscope slide with a rectangular indentation that creates a chamber with a laser-etched grid of perpendicular lines,
In addition, muscle cells, also known as muscle fibers or myocy......

How can cancer immunotherapy be enhanced?

T cells are responsible for defending against pathogen infection, tumorigenesis, and are the primary cells mobilized by tumor immunotherapy. But cancer cells have a variety of tricks at their disposal to evade immune screening and attack.
How to make immune cells more active and promote the efficacy of tumor immunotherapy?
Scientists from the national cancer institute found that dying cancer cells release potassium ions, a compound in high concentrations that can damage T cells' metabolism and nutritional intake, causing them to go hungry and strike.
But, amazingly, high levels of potassium also alter the epigenetic modifications of t-cells, keeping them "stem cell like." In other words, in a tumor, these stem cell-like T cells just keep reproducing themselves, but fail to differentiate and mature into killer T cells.
This means that even if T cells were present, the tumour would not be attacked because of its "stem cell nature" and would continue to grow.
The researchers speculate that using this "stem cell property" could improve the effectiveness of cancer immunotherapy.
Currently, immunotherapy has brought positive hope to cancer patients, especially some patients with advanced stage achieved complete remission. But the cancer immunotherapy response rate is only 25 to 30 percent, and many patients have tumors that do not respond to the treatment, and scientists are trying to figure out why.
In addition, some immunotherapies, such as car-t and checkpoint inhibitors, are limited by T cell life. The cancer-fighting T cells in a tumor "run out" and die. So researchers are looking at ways to help t-cells used in immunotherapy last longer, and even encourage them to replicate and amplify.
The emergence of "potassium ions" offers hope. In the new study, Dr Nicholas Restifo found that t-cells grown in high-potassium environments also had "stem cell properties."
What's more, when researchers took these t-cells from tumor ti......

Serotonin regulates gene expression in neurons

    Serotonin or 5-hydroxytryptamine (5-HT) is an important monoamine neurotransmitter. It is responsible for transmitting signals between brain neurons and for regulating mood.
    Recently, scientists in China and the United States discovered that serotonin also regulates gene expression in neurons.
    By Western blotting and recombinant TGM2 enzyme analysis, they confirmed that histone H3 is an endogenous substrate for serotoninization. Chemical modifications of histones can mediate diverse DNAtemplated processes, including gene transcription1–3. The study proved that serotonylation of glutamine occurred at position 5 (Q5ser) on histone H3 in organisms that produce serotonin (also known as 5-hydroxytryptamine (5-HT)).
    The researchers demonstrate that tissue transglutaminase 2 can serotonylate histone H3 tri-methylated lysine 4 (H3K4me3)-marked nucleosomes, resulting in the presence of combinatorial H3K4me3Q5ser in vivo. H3K4me3Q5ser displays a ubiquitous pattern of tissue expression in mammals, with enrichment observed in brain and gut, two organ systems responsible for the bulk of 5-HT production. Genomewide analyses of human serotonergic neurons, developing mouse brain and cultured serotonergic cells indicate that H3K4me3Q5ser nucleosomes are enriched in euchromatin, are sensitive to cellular differentiation and correlate with permissive gene expression, phenomena that are linked to the potentiation of TFIID4–6 interactions with H3K4me3. Cells that ectopically express a H3 mutant that cannot be serotonylated display significantly altered expression of H3K4me3Q5ser-target loci, which leads to deficits in differentiation.
    These results identify a direct role for 5-HT, independent from its contributions to neurotransmission and cellular signalling, in the mediation of permissive gene expression. The research helps people better understand a variet......

The method of photodynamic acidification cancer therapy

Researchers from the United States pioneered a new method called photodynamic cancer therapy, which uses specific light waves to illuminate tumors and actives the photoactive drug in the tumor, and then the tumor is destroyed by a luminescent chemical reaction.
A chemical compound (nitrobenzaldehyde) was injected into the tumor and the chemical spreads into the tissue, then aimed a beam of light at the tissue. The light caused the inside of the cell to become very acidic, causing the cell to commit suicide. Within two hours, the researcher estimated that up to 95% of targeted cancer cells have died.
The researcher said: "Although there are many different types of cancer, they all have one thing in common: they are very sensitive to this induced cell suicide." The method was tested in triple-negative breast cancer, which is the most invasive and intractable cancer that is most difficult to treat. After one time of treatment in the laboratory, the tumor stopped growth and the survival rate of the mouse was double.
In the past two years, the researchers have developed photodynamic cancer therapies which have reached a non-invasive level. Now we only need to inject nitrobenzaldehyde liquid, and then irradiate ultraviolet light to cause anti-cancer reaction. The researcher also began to develop a nanoparticle that can be injected into the body to target cancer cells. By activating the nanoparticle with a wavelength of light, it can penetrate the skin, muscles and bones harmlessly and still activate the anti-cancer nanoparticle.
The researcher hopes that his non-invasive approach will help doctors to identify uncertain tumors in certain areas, such as the brain stem, aorta or spine. It can also help patients who have already received the maximum amount of radiation – these people are no longer able to cope with the scars and pains caused by chemotherapy, or children with cancer.