Chapter 11 Self-check questions

. Which one of the following modifies the risk of specific cancers in response to red meat consumption?

Polymorphisms in the N-acetyltransferase gene.

The quantity of tyrosinase enzyme produced by the individual.

The relative quantities of N-acetyltransferase and tyrosinase.

Frying red meat can decrease the risk of cancer.

. Which one of the following inherited diseases of metabolism can affect cancer risk?

Carriers of the inactive aldehyde dehydrogenase allele, common in Asians, are at decreased risk for alcohol-related esophageal cancer.

Tyrosinemia type I causes the accumulation of carcinogenic metabolites.

Phenylketonuria inhibits tumor suppressor genes.

Deficiencies in melanin production cause fatty liver and an increase in liver cancer.

. Which observation below is true and links energy metabolism with cancer?

AMP-activated protein kinase (AMPK), a key metabolic enzyme, inhibits the activity of p53.

LKB1 activates AMPK. Germline mutations of the LKB1 gene cause Peutz–Jeghers syndrome. Patients with this syndrome have an increased risk of cancer.

AMPK, a serine/threonine kinase, acts as an oncogene.

Metformin, a drug used to treat diabetes, activates AMPK. Results from initial studies suggest that cancer risk is increased in diabetics taking metformin.

. Epidemiological studies suggested that diets rich in beta-carotene reduced lung cancer. As shown by the CARET study, supplements of β -carotene had which of the following effects?

Increased lung cancer in high-risk individuals.

Decreased lung cancer in high-risk individuals.

Decreased lung cancer in healthy individuals.

Decreased skin cancer by causing an orange tint to the skin.

. Which one of the following statements about why foods can act as a cancer-causative factor is true?

All foods cause inflammation.

They may carry carcinogens.

They may carry cancer cells into the body.

They may act as antioxidants.

. Which of the following mechanisms of action of obesity, as a cancer risk factor, is supported by recent evidence?

It induces the enzyme alcohol dehydrogenase to form acetaldehyde that can directly bind to DNA.

It causes a change in the gut microbiome (more Gram-positive bacteria), which results in an increase of a bacterial metabolite, deoxycholic acid, that can damage DNA.

It increases the formation of a metabolite of cholesterol, 27-hydroxycholesterol (27HC), an antagonist of the estrogen receptor blocking estrogen-responsive genes.

It induces Phase II (detoxification) enzymes.

. Which one of the following is not a mechanism by which fruits and vegetables act to reduce cancer risk?

Regulating the expression of genes that code for Phase II metabolizing enzymes.

Being a source of dietarty minerals such as iron and zinc which is associated with a lower risk of lung cancer.

Inducing proliferation.

Free radical scavenging.

. Which one of the following options correctly describes how genes that contain an ARE in their promoter regions are activated?

By vitamins and their receptors such as the vitamin D and its receptor.

By antibiotics via transcription factor NRF2.

By antioxidants via the inactivation of KEAP1 and the stabilization of transcription factor NRF2.

By antioxidants via the inactivation of IKK and activation of transcription factor NF-κB.

. Which one of the following statements about the Warburg effect is correct?

It describes the observation that cancer cells carry out anaerobic glycolysis, converting glucose to lactate in the absence of oxygen.

It describes the basis for the diagnostic technique called PET, which works on the basis that tumor cells exhibit a decreased uptake of glucose compared to normal cells.

It describes the observation that cancer cells carry out aerobic glycolysis, converting glucose to lactate in the presence of oxygen.

It describes the basis for the diagnostic technique called NMR.

. The cellular receptor for vitamin D is:

related to the EGF receptor.

a transmembrane G protein receptor.

a nuclear transmembrane receptor.

a ligand-dependent transcription factor that belongs to the steroid hormone receptor superfamily.

. The Warburg effect is characterized by an excess production of lactate.
Which of the following is false?

Lactate is a waste product.

Lactate is an important source of fuel.

Lactate is an important precursor for gluconeogenesis.

Lactate is an important signaling molecule as it is a ligand for the G-protein coupled receptor 81 (GPR81).

. With regards to therapeutic strategies that target cancer cell metabolism, which of the following are false?

Strategies of both administration of an enzyme and the inhibition of an enzyme have been approved.

Specific high protein diets have been approved as a treatment for lung cancer.

Blocking a mutant enzyme can inhibit the production of a oncometabolite.

Depletion of an amino acid can interfere with the high rate of protein synthesis in acute lymphoblastic leukemia.

. Which of the following demonstrate a true link between intermediary metabolites and epigenetics?

ATP is a co-factor for AMP-activated protein kinase (AMPK).

Acetyl CoA is a universal donor for deacetylation reactions.

Sirtuins are kinases that are regulated by acetyl CoA.

Sirtuins are a family of NAD+-dependent histone deacetylases.

Quiz Content