Zbtb7

Key takeaways

Zbtb7 belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Zbtb7 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Zbtb7 from memory before moving on to harder problems.

Reference excerpt

Zbtb7, whose protein product is also known as Pokemon, is a gene that functions as a regulator of cellular growth and a proto oncogene. Zbtb7 is a member of the POK (POZ and Krüppel) family of genes, and the ZBTB protein family that contains zinc finger and BTB domains. It is also known as LRF10 (leukemia/lymphoma-related factor), OCZF11 (osteoclast-derived zinc finger), and FBI1 (1-3) (fourteen-three-three beta interactant). Zbtb7 is a transcription factor that regulates pathways involved in cell growth and transcription and it specifically represses many activities. When this gene binds to a consensus sequence, it prevents transcription by controlling the conformation of chromatin and bringing other transcription factors to gene regulation sites. This gene controls access to gene transcription regulation regions. Zbtb7 prevents SP1, a transcription factor, from binding to DNA which will halt the process of transcribing DNA to RNA. Downstream effects of Zbtb7 activity include failure to transcribe ARF, a critical tumor suppressor. Zbtb7 is also involved in the regulation of p53, another tumor suppressor gene. As an oncogene, Zbtb7 is overexpressed in many types of cancer, including lung, liver, prostate, and oral.

Oncogenic studies on Zbtb7 In initial studies using mouse embryonic fibroblasts, researchers found that in the absence of Zbtb7, cellular pathways that convert normal cells into tumor cells did not develop. However, when Zbtb7 was overexpressed, pathways for the transformation of normal cells to cancer cells resulted, both in vitro and in vivo. From these observations, researchers concluded that Zbtb7 is often overexpressed in human cancers, and so it can be used to understand biological pathways and patient prognosis. The relationship between Zbtb7 and breast cancer has been investigated. Based on a clinical study, it was concluded that the expression of Zbtb7 is related to the severity of the grade of cancer. High expression of the gene was apparent in patients with grades II and III cancer, while low expression of the gene was found in patients with grade I and II tumors. Zbtb7 can also serve as a biomarker for patient survival. It was shown that patients with low expression of Zbtb7 were less likely to experience a recurrence in the following five years compared to those with high expression of the gene. Consistent results were concluded in a later study investigating the relationship between Zbtb7 expression and transitional cell carcinoma (TCC) in the bladder. Higher expression of this gene was associated with later stage, more severe grade, higher recurrence, and lower survival. As a result, it is assumed that Zbtb7 expression may be related to the onset, growth, and proliferation of TCC tumors. Researchers stated that some of their data is not statistically significant due to a small sample size and failure to follow-up with patients, so further study is recommended to verify the relationship between Zbtb7 and TCC patient outcomes. Zbtb7 has also been studied in association with renal carcinoma. The study indicated that Zbtb7 was present in abundance in renal carcinoma specimens and that overexpression of the gene was related to increases in cell growth and invasion into other cells and tissues. However, when Zbtb7 was silenced, this activity was not apparent. miR-137, a tumor suppressor miRNA was found to decrease the expression of Zbtb7. When Zbtb7 levels increase, it is capable of binding to the promoter region and preventing transcription of miR-137. Together, Zbtb7 and miR-137 form an autoregulatory loop that mediates the onset, growth, and spread of cancer. Zbtb7 is abundantly expressed in colorectal cancer (CRC) as well. Treatment for CRC includes administration of 5-Fluorouracil (5-FU), chemotherapy also used to treat other cancers, such as pancreatic cancer and breast cancer. Some CRC patients have developed resistance to 5-FU. It has been shown that overexpression of Zbtb7 may increase 5-FU resistance through the NF-[kappa]B signaling pathway and thus allow for further proliferation of cancer cells. However, the introduction of SN50, an NF-[kappa]B inhibitor reverses resistance caused by Zbtb7. Therefore, the relationship between Zbtb7 and NF-[kappa]B may be important in reducing 5-FU resistance in CRC patients.

Etymology Pokemon is the name given to the protein product of Zbtb7 gene by the research team at Memorial Sloan Kettering Cancer Center (MSKCC), which discovered its oncogenic function. It stands for "POK erythroid myeloid ontogenic [sic] factor" and is most likely a backronym of the Pokémon media franchise. The Pokémon Company threatened MSKCC with legal action in December 2005 for creating an association between cancer and the media franchise, and as a consequence MSKCC is now referring to it by its gene name Zbtb7.

Genes ZBTB7A ZBTB7B

See also Sonic hedgehog, a protein that is named after Sonic the Hedgehog, a video game character. Pikachurin, a retinal protein named after Pikachu, a Pokémon.

References

Worked examples

Example 1 — a first encounter with Zbtb7

Start with the simplest possible case. Write down what Zbtb7 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 Zbtb7 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 Zbtb7 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 Zbtb7

In research: Zbtb7 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 Zbtb7 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: Zbtb7 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Oncogenes, Pokémon, so understanding it makes those chapters shorter.
In everyday life: Look for Zbtb7 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.

How to study Zbtb7 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Zbtb7 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 Zbtb7 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Zbtb7 in simple terms?

Zbtb7, whose protein product is also known as Pokemon, is a gene that functions as a regulator of cellular growth and a proto oncogene. Zbtb7 is a member of the POK (POZ and Krüppel) family of genes, and the ZBTB protein family that contains zinc finger and BTB domains.

Why does Zbtb7 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 Zbtb7?

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 Zbtb7.