Bad News for Smokers

June 12, 2015 by

By Medical Discovery News

June 5, 2015

Person smoking a cigarette

Smoking isn’t the only thing that raises your risk of lung cancer. As it turns out, your DNA can have that effect too.

A scientific study scanned the genomes, the entire genetic code, of 11,000 people of European descent in an effort to identify if there was any correlation between gene sequences and a common form of lung cancer, non-small cell carcinoma. They discovered that variants of certain genes increase a person’s susceptibility to developing lung cancer, especially in smokers.

One of the three gene variants they identified, named BRCA2, can double a smoker’s chance for developing lung cancer. BRCA2 is a tumor suppressor gene. It encodes a protein involved in the repair of damaged DNA, which is critical to ensure the stability of cell’s genetic material. When cellular DNA is damaged, there are several ways for the body to detect and repair that damage. If the damage to DNA cannot be repaired, then the cell is programmed to die by a process called apoptosis in order to prevent the damage being passed on to its daughter cells.

Like other tumor suppressor genes, the BRCA2 protein helps to repair breaks in DNA. It also prevents damaged cells from growing and dividing too rapidly. Variants of BRCA2 associated with breast, ovarian, and now lung cancers produce proteins that do not repair DNA damage properly. This causes cells to accumulate additional mutations, which can lead to cells that grow and divide uncontrollably. Such mutations lead to an increased risk of developing cancer.

Scientists have discovered over 800 mutations of BRCA2 that cause disease, including breast, ovarian, lung, prostate, pancreatic, fallopian, and melanoma cancers. Most of the mutations result from the insertion or deletion of a few letters of genetic code into the part of the gene that code for a protein. This disrupts the production of the BRCA2 protein and results in a shortened and nonfunctional form of the BRCA2 protein.

Lung cancer is a leading killer of Americans. Nearly 160,000 Americans will die from lung cancer this year, representing 27 percent of all cancer deaths. Active smoking causes close to 90 percent of lung cancers.

The good news from this discovery is that since scientists first linked BRCA2 to an increased risk of breast cancer, new therapies have been developed. Current treatments for breast and ovarian cancers could be effective with BRCA2-associated lung cancers, such as PARP inhibition.  PARP1 is another protein involved in repairing DNA damage. When one of two strands of DNA are broken or nicked, PARP1 moves to the region and recruits other proteins to the site to repair the damage. Many chemotherapy agents kill cancer cells by inducing DNA damage in the tumor and inhibiting PARP1. This doesn’t allow cancer cells to repair damage and makes them more susceptible to chemotherapy and radiation therapy. Now that we know this gene is linked to lung cancer, such therapies may be more effective in treating lung cancer and saving lives.

For a link to this story, click here.

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Cigars Are No Better

May 15, 2015 by

May 15, 2015

By Medical Discovery News

Person smoking a cigarette

A common argument made by those who smoke cigars is that they are safer than cigarettes.  However, several studies argue that this is not true.

Cigar smoking has increased dramatically in the U.S. Between 2000 and 2011, small cigar sales rose 65 percent and large cigar sales increased 233 percent. Americans smoked more than 13 million cigars in 2010, twice the number from 2000. About 13.4 million people age 12 or older smoke cigars. A cigar culture has arisen, with cigar bars or clubs, shops with walk-in humidors, and magazines for those who consider themselves cigar connoisseurs. Their use among sports figures and celebrities has made them seem fashionable or sophisticated, a symbol of status or success.

The tobacco in cigars is cured and fermented to enhance the flavor, but this process also increases the amounts of harmful ingredients. Cigars come in three basic sizes, but the classic cigars are the large ones that contain more than half an ounce of tobacco, and some contain as much as an entire pack of cigarettes.

Just like cigarettes, cigars contain nicotine and can be very addictive. Most people who smoke cigars do not inhale, and therefore the nicotine is absorbed more slowly. However, cigar smoke dissolves more easily in saliva than cigarette smoke, enhancing the amount of nicotine absorbed.  Smokers absorb one to two milligrams of nicotine out of the eight total milligrams in cigarettes. The large cigars contain anywhere from 100 to over 400 milligrams of nicotine, and the amount a person absorbs varies greatly depending on how long the cigar is smoked, how many puffs are taken, and how much smoke is inhaled. Second- and third-hand cigar smoke is dangerous, just like it is with cigarettes.

In one study, scientists measured the levels of two biomarkers for tobacco as well as arsenic and lead in over 25,000 cigar smokers. Cigar smokers had higher levels of these carcinogens than nonsmokers and equal levels to cigarette smokers. Overall, the study found that cigars are not safer than cigarettes. Cigar smokers are less likely to develop lung cancer than cigarette smokers, but they are at higher risks of developing other cancers.

Those who inhale while smoking cigars are more likely to develop laryngeal cancer, lung cancer, bladder cancer, pancreatic cancer, and cancers of the tongue, mouth, or throat than nonsmokers. Even those who don’t inhale the smoke directly still inhale the secondhand smoke and are at an increased risk of lung cancer. Cigar smokers are four to 10 times more likely to die from cancers of the mouth, larynx, and esophagus than nonsmokers.

Cigar smoking also increases the risk of other diseases including emphysema, chronic bronchitis, heart attacks, gum disease, and erectile dysfunction. One long-term study determined that cigar or pipe smoking costs people 10 years on average – they spent an extra five years in bad health and died five years earlier.

So before you take up cigars in an attempt to look cool, ask yourself if your image is more important than your health.

For a link to this story, click here.

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More Bad News for Smokers

October 27, 2014 by

Oct. 24, 2014

By Medical Discovery News

Lung X-ray

Smoking isn’t the only thing that raises your risk of lung cancer. As it turns out, your DNA can have that effect too.

A scientific study scanned the genomes, the entire genetic code, of 11,000 people of European descent in an effort to identify if there was any correlation between gene sequences and a common form of lung cancer, non-small cell carcinoma. They discovered that variants of certain genes increase a person’s susceptibility to developing lung cancer, especially in smokers.

One of the three gene variants they identified, named BRCA2, can double a smoker’s chance for developing lung cancer. BRCA2 is a tumor suppressor gene. It encodes a protein involved in the repair of damaged DNA, which is critical to ensure the stability of cell’s genetic material. When cellular DNA is damaged, there are several ways for the body to detect and repair that damage. If the damage to DNA cannot be repaired, then the cell is programmed to die by a process called apoptosis in order to prevent the damage being passed on to its daughter cells.

Like other tumor suppressor genes, the BRCA2 protein helps to repair breaks in DNA. It also prevents damaged cells from growing and dividing too rapidly. Variants of BRCA2 associated with breast, ovarian, and now lung cancers produce proteins that do not repair DNA damage properly. This causes cells to accumulate additional mutations, which can lead to cells that grow and divide uncontrollably. Such mutations lead to an increased risk of developing cancer.

Scientists have discovered over 800 mutations of BRCA2 that cause disease, including breast, ovarian, lung, prostate, pancreatic, fallopian, and melanoma cancers. Most of the mutations result from the insertion or deletion of a few letters of genetic code into the part of the gene that code for a protein. This disrupts the production of the BRCA2 protein and results in a shortened and nonfunctional form of the BRCA2 protein.

Lung cancer is a leading killer of Americans. Nearly 160,000 Americans will die from lung cancer this year, representing 27 percent of all cancer deaths. Active smoking causes close to 90 percent of lung cancers.

The good news from this discovery is that since scientists first linked BRCA2 to an increased risk of breast cancer, new therapies have been developed. Current treatments for breast and ovarian cancers could be effective with BRCA2-associated lung cancers, such as PARP inhibition.  PARP1 is another protein involved in repairing DNA damage. When one of two strands of DNA are broken or nicked, PARP1 moves to the region and recruits other proteins to the site to repair the damage. Many chemotherapy agents kill cancer cells by inducing DNA damage in the tumor and inhibiting PARP1. This doesn’t allow cancer cells to repair damage and makes them more susceptible to chemotherapy and radiation therapy. Now that we know this gene is linked to lung cancer, such therapies may be more effective in treating lung cancer and saving lives.

For a link to this story, click here.

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Warning: Third-hand Smoke

September 13, 2014 by

Sept. 5, 2014

By Medical Discovery News

Smoke

Science has long proven that smoking is bad for you and those around you, with 90 percent of lung cancer cases caused by smoking. Even second-hand smoke is dangerous enough to warrant banning smoking in public places. The idea of third-hand smoke premiered in 2009, and scientific evidence shows that it too can harm human health.

Third-hand smoke is the many toxic compounds from tobacco smoke that settle onto surfaces (particularly fabrics) such as carpet, furniture, and the inside of a car. Researchers have identified chemicals in third-hand cigarette smoke called NNA and NNK that can bind to DNA, a person’s genetic information, and cause damage and mutations that could lead to cancer.

There are 4,000 known pollutants in cigarette smoke including a large number that cause DNA damage. Many of them have been found in the carpets, walls, furniture, dust, clothing, hair, and skin of smokers long after they’ve smoked a cigarette. The pollutants from smoke can accumulate over time, making the environment increasingly toxic. Mainstream smoke has more than 60 known carcinogens, which cause cancer, and other toxins, many of which are present in second- and third-hand smoke. Nonsmokers are exposed to these toxic compounds when they inhale, touch, or ingest them off of surfaces containing third-hand smoke. To make matters worse, some of the smoke residue can undergo a chemical transformation into secondary compounds when it interacts with other indoor pollutants, like ozone and nitrous acid. For example, nicotine reacts with ozone in the atmosphere to produce byproducts and ultrafine particles that can trigger asthma attacks.

Other secondary products such as NNA and a related compound called NNK are also formed. A recent study aimed to discover what level of third-hand smoke mutagens and carcinogens a nonsmoker might be exposed to in realistic scenarios, and whether these levels would be high enough to cause damage to DNA or other adverse effects. Unrepaired DNA damage can lead to mutations and increase the risk of developing cancer. They concluded that human cells exposed to third-hand smoke or secondary compounds had increased DNA damage within 24 hours. These results provide evidence that third-hand smoke does include carcinogens from cigarette smoke and the environment. The study also showed that NNA and NNK have damaging effects on developing lungs, making them particularly harmful to infants.

Smokers themselves are giving off third-hand smoke toxins, so going outside to smoke helps but is no solution. It is unclear how long toxic third-hand smoke compounds continue to be a risk. Depending on the compound, they may linger for hours, days, weeks, or longer. When smokers quit they should take steps to rid their homes and vehicles of third-hand smoke. This is potentially a time-consuming and expensive proposition but it is worth doing.

In 2011, 44 million American adults smoked cigarettes and 34 million of them smoked every day. Smoking causes one in five deaths, killing nearly 500,000 people in the U.S. every year. That is more deaths than HIV, illegal drugs, alcohol, motor vehicle accidents, and firearms combined. Is it really worth it?

For a link to this story, click here.

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An Aspirin A Day

March 29, 2013 by

March 29, 2013

By Medical Discovery News

New research shows that aspirin truly deserves its nickname as the wonder drug, since now it even helps fight cancer. It’s naturally found in willow bark, which has been used as herbal medicine for thousands of years. People have been taking aspirin in its current for over 100 years.

Ancient Greeks used ground willow bark to treat fevers and control pain during in childbirth. Then, in the early 1800s, English physicians and scientists wanting to discover the key to willow bark’s effect isolated its active component, salicin. In 1890 a German chemist named Friedrich Bayer (sound familiar?) created a synthetic salicin molecule called acetylsalicylic acid. This derivative was less irritating to the stomach than willow bark and became the modern form that lines drugstore shelves. 

Since then, researchers have been finding even more medical uses for aspirin. In the 1960s, scientists began exploring aspirin’s ability to thin blood and tested its usefulness in preventing heart disease. To summarize many extensive clinical trials, it is now generally believed that taking low-dose aspirin on a daily basis helps reduce the chances of a second heart attack (but not the first) in men. But these studies also revealed some negative side effects of regular aspirin use, including bleeding ulcers and hemorrhaging retinas. 

Recent studies may have uncovered another, quite wonderful, effect of aspirin – reducing the risk of some common cancers. Initial studies found the occurrence of colorectal cancer was lower in those who took aspirin regularly. These studies followed individuals who took aspirin for its cardiovascular benefits, but also ended up decreasing their risk of developing certain tumors by almost 40 percent. And low-dose aspirin also appeared to reduce the spread of tumors in people with established cancer.

In a 2010 British study, those taking daily aspirin for at least five years reduced their risk of dying from colorectal, esophageal, stomach, pancreatic, brain, lung, and prostate cancers by more than 20 percent. These studies also cited issues of bleeding in the stomach and retinas, especially in older individuals. New guidelines for aspirin therapy suggest starting an aspirin regime at age 50 and stopping by age 70 in order to reduce this risk.

Several properties of aspirin might explain its cancer-fighting abilities. Aspirin inhibits enzymes called cyclooxygenases or COX, which normally convert a type of fatty acid into compounds that protect the stomach lining. This may be why aspirin can lead to stomach irritation, but may also explain why aspirin works well as an anti-inflammatory, since COX can contribute to inflammation. And preventing inflammation also prevents the growth of tumor cells.

Given its ability to combat the nation’s two most serious killers, the potential for expanding low-dose aspirin therapy looks positive. Overall, these results have scientists on the verge of declaring aspirin the first “general anticancer drug.” Of course, individuals should consult their physician before starting any drug regime. 

For a link to this story, click here.

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