biology

Metastasis suppressor

Metastasis suppressor is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Metastasis suppressor rather than just read about it. In short: A metastasis suppressor is a protein that acts to slow or prevent metastases (secondary tumors) from spreading in the body of an organism with cancer. Metastasis is one of the most lethal cancer processes.

Key takeaways

Metastasis suppressor belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Metastasis suppressor to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Metastasis suppressor from memory before moving on to harder problems.

Reference excerpt

A metastasis suppressor is a protein that acts to slow or prevent metastases (secondary tumors) from spreading in the body of an organism with cancer. Metastasis is one of the most lethal cancer processes. This process is responsible for about ninety percent of human cancer deaths. Proteins that act to slow or prevent metastases are different from those that act to suppress tumor growth. Genes for about a dozen such proteins are known in humans and other animals.

Background The treatment of cancer usually aims to destroy and/or stop the growth of the primary tumor. Major improvements in the methods of surgery, radiation, and chemotherapy have taken place, but corresponding improvements in patient survival have not always followed. Treatments that focus on the primary cancer typically do not address metastasis. Metastasis suppressors act by different mechanisms than tumor suppressors and do not affect primary tumors. Tumor suppressors, however, also inhibit metastasis, since metastasis is dependent upon tumorigenicity. Metastasis suppressors were first identified using microcell-mediated chromosome transfer (MMCT), which introduces chromosomes into intact recipient cells. Chromosomes 1, 6, 7, 8, 10, 11, 12, 16 and 17 harbor metastasis suppressor genes. MicroRNAs (miRNAs) are a class of gene regulators that bind the 3′ untranslated regions of target messenger RNAs, leading to either suppression of their translation or acceleration of their degradation. In cell MDA-MB-231 and its metastatic variant, six miRNAs displayed lower expression in metastatic cells. Among them, miR-335 and miR-126 suppress metastasis without affecting primary tumor growth. miR-335 targets multiple pathways, including SOX4, MERTK, PTPRN2 and TNC, which contribute to metastasis-suppression. miR-335 expression is correlated with metastasis-free survival in clinical breast cancer.

Clinical applications Metastasis suppressors can potentially serve as prognostic markers, therapeutic targets and predictors for treatment response.

Prognosis High NM23 expression is correlated with good prognosis in multiple tumor types, including breast cancer. KAI1, PEBP1 and RECK expression correlate with improved survival in multiple tumor types, including colorectal cancer. High expression of CTGF is correlated with improved survival in colorectal cancer, non-small cell lung carcinoma and gallbladder cancer, but the correlation is reversed in esophageal cancer and glioma.

Targets Patients with NM23 -positive ovarian cancer respond better to cisplatin than patients with NM23-negative tumors and esophageal squamous cell carcinoma. NM23 expression is correlated with increased survival after cisplatin treatment following surgery. Unlike tumor suppressors, most metastasis suppressors are downregulated in clinical tumor samples rather than mutated. Activation of these metastasis suppressors can potentially block metastasis and improve survival. The promoter region of NM23 contains glucocorticoid response elements that can elevate NM23 expression. Treating human breast cancer cells with dexamethasone medroxyprogesterone acetate (MPA) increases NM23 expression.

Genes Genes for about a dozen metastasis-suppressing proteins are known in humans and other animals, including BRMS1, CRSP3, DRG1, KAI1, SDPR, KISS1, NM23 and various TIMPs. Most act by altering aspects of signal transduction.

… excerpt ends here. Continue reading the full article.

Worked examples

Example 1 — a first encounter with Metastasis suppressor

Start with the simplest possible case. Write down what Metastasis suppressor claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Metastasis suppressor before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Metastasis suppressor ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Metastasis suppressor

In research: Metastasis suppressor appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Metastasis suppressor in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Metastasis suppressor is common in secondary-school and first-year university syllabi. It links to neighbouring topics Antineoplastic drugs, Proteins, so understanding it makes those chapters shorter.
In everyday life: Look for Metastasis suppressor outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Metastasis suppressor in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Metastasis suppressor means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Metastasis suppressor out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Metastasis suppressor in simple terms?

Why does Metastasis suppressor matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Metastasis suppressor?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Metastasis suppressor.