- Email: [email protected]
PROTEIN DETERS HEAD, NECK CANCER GROWTH, STUDY SHOWS
NEWS
GUM CHEWING LINKED TO HEADACHES IN CHILDREN, RESEARCHERS REPORT
C
hewing gum often is responsible for headaches in young children and teenagers, say researchers in the January issue of Pediatric Neurology. A research team led by Nathan Watemberg, MD, chairman of the Child Development Institute and the Child Neurology Unit at Meir Medical Center in Kfar Saba, Israel, which is affiliated with Tel Aviv University School of Medicine, consecutively recruited 30 patients ranging in age from 6 to 19 years who had chronic migraine or tension headaches and chewed gum between one and six hours per day. Researchers asked the participants to fill out a questionnaire pertaining headache characteristics, potential triggers, family history of headaches and gum-chewing habits. They then classified the participants into four groups depending on the number of hours they chewed gum daily. Researchers had the participants discontinue chewing gum for one month and then interviewed them. Nineteen of the patients reported that their headaches went away entirely, and seven reported a decrease in the frequency and intensity of headaches. To test the results, researchers asked 26 of the participants to resume gum chewing for two weeks. All of these participants reported a return of their symptoms within days. Dr. Watemberg says his team’s findings can be put to use immediately. By advising teenagers with chronic headaches who chew gum to simply stop chewing gum, doctors can provide many of them with quick and effective treatment without the need for diagnostic tests or medications. NEW CLEFT LIP AND PALATE SYNDROME GENE IDENTIFIED, SAY RESEARCHERS
S
cientists have identified a gene that may be responsible for one type of cleft lip and palate syndrome,
according to an article published in the January issue of American Journal of Human Genetics. An international team led by researchers from Karolinska Institutet in Stockholm has identified a gene related to Van der Woude syndrome (VWS), the most common syndrome that involves clefts. Researchers conducted a study of a large family from Finland. Family members had been diagnosed with VWS but did not have mutations in a gene called interferon regulatory factor 6 (IRF6). Approximately 70 percent of people with VWS have an IRF6 mutation. When researchers compared the DNA of affected family members with the DNA of healthy family members, they discovered another gene—grainyheadlike 3 (GRHL3)—that was mutated only in the affected family members. They found that the same gene was altered in seven additional families with VWS in which no IRF6 mutations had been found. To further investigate the role of GRHL3 in oral abnormalities, researchers at six laboratories studied human mutations of this gene in zebra fish and mouse models. They found that mouse embryos that did not have the GRHL3 gene could not form proper palates and were born with clefts. They also found that GRHL3 encodes a transcription factor that is regulated by IRF6. The authors concluded that both genes are required for a proper formation of the palate and that they probably function in separate but convergent molecular pathways. “The discovery of a new gene, GRHL3, responsible for the most common of the syndromic forms of cleft lip and palate means that researchers or clinicians with collections of families or isolated cases with cleft lip and palate, syndromic or non-syndromic, now will be able to look for mutations in this gene,” said lead author Myriam PeyrardJanvid, PhD, Department of Biosciences and Nutrition, Karolinska Institutet. “As it has been shown for IRF6, one or several polymorphisms
in GRHL3 might be found to be associated with increased risk of clefts in non-syndromic cases.” The Swedish Research Council and the National Institutes of Health funded this study. PROTEIN DETERS HEAD, NECK CANCER GROWTH, STUDY SHOWS
S
JADA 145(3)
cientists at the National Institute of Dental and Craniofacial Research found that blocking a certain protein inhibited the proliferation of head and neck squamous cell carcinoma, according to a study published in the February issue of Molecular Oncology. In an experiment involving tissue samples of hundreds of head and neck cancer patients, an NIDCR team led by Silvio Gutkind, PhD, chief of NIDCR’s Oral and Pharyngeal Cancer Branch, found that p38 kinase was active in most samples. They reported that the most malignant tissue samples had the highest activity of p38, and the least malignant samples had the lowest p38 activity. The normal oral tissue used as a control had no p38 activity. When researchers turned off p38 activity in human oral cancer cells and transplanted these cells into laboratory mice, they found that the oral cancer cells without p38 activity were smaller than those with p38 activity. In addition, turning off p38 activity lessened the growth of new
COMING IN APRIL
dHospital-based emergency department visits regarding dental conditions dUsing stereophotogrammetry technology to make intraoral digital impressions for implants dOral care behaviors after purging in women with bulimia Look for this and more in the April issue of JADA.
http://jada.ada.org
March 2014
235
NEWS
blood vessels, which cancers rely on for growth and the ability to spread to other parts of the body. In the next phase of the study, they tested SB203580—a drug that is known to block p38 activity. SB203580 reduced the growth of head and neck cancer cells in the laboratory. When the NIDCR team then used SB203580 to treat human head and neck cancers that had been transplanted into lab mice, they found that SB203580 made the cancers smaller. The next step, Dr. Gutkind says, is to test a new generation of drugs that inhibit p38.
236
JADA 145(3)
http://jada.ada.org
CORRECTIONS
I
n the February issue, the article “Fluoride Toothpaste Use for Young Children” by the American Dental Association (ADA) Council on Scientific Affairs (JADA 2014;145[2]:190-191) contained two errors. dIt should have contained an additional citation. The third sentence in the first paragraph—“To assess the effectiveness and safety of using fluoride toothpaste for young children, the Council recommended a systematic review of the evidence”— should have referenced the systematic review, which also appeared
March 2014
in the February issue: “Fluoride Toothpaste Efficacy and Safety in Children Younger Than 6 Years: A Systematic Review,” by J. Timothy Wright, DDS, MS, and colleagues (JADA 2014;145[2]:182-189). dThe biographical information for one of the authors was incomplete. Clifford W. Whall, PhD, is the interim senior director, ADA Council on Scientific Affairs, and the director, Acceptance Program, ADA Council on Scientific Affairs. JADA regrets the errors. Q Compiled by Amy E. Lund, senior editor.
GUM CHEWING LINKED TO HEADACHES IN CHILDREN, RESEARCHERS REPORT
C
hewing gum often is responsible for headaches in young children and teenagers, say researchers in the January issue of Pediatric Neurology. A research team led by Nathan Watemberg, MD, chairman of the Child Development Institute and the Child Neurology Unit at Meir Medical Center in Kfar Saba, Israel, which is affiliated with Tel Aviv University School of Medicine, consecutively recruited 30 patients ranging in age from 6 to 19 years who had chronic migraine or tension headaches and chewed gum between one and six hours per day. Researchers asked the participants to fill out a questionnaire pertaining headache characteristics, potential triggers, family history of headaches and gum-chewing habits. They then classified the participants into four groups depending on the number of hours they chewed gum daily. Researchers had the participants discontinue chewing gum for one month and then interviewed them. Nineteen of the patients reported that their headaches went away entirely, and seven reported a decrease in the frequency and intensity of headaches. To test the results, researchers asked 26 of the participants to resume gum chewing for two weeks. All of these participants reported a return of their symptoms within days. Dr. Watemberg says his team’s findings can be put to use immediately. By advising teenagers with chronic headaches who chew gum to simply stop chewing gum, doctors can provide many of them with quick and effective treatment without the need for diagnostic tests or medications. NEW CLEFT LIP AND PALATE SYNDROME GENE IDENTIFIED, SAY RESEARCHERS
S
cientists have identified a gene that may be responsible for one type of cleft lip and palate syndrome,
according to an article published in the January issue of American Journal of Human Genetics. An international team led by researchers from Karolinska Institutet in Stockholm has identified a gene related to Van der Woude syndrome (VWS), the most common syndrome that involves clefts. Researchers conducted a study of a large family from Finland. Family members had been diagnosed with VWS but did not have mutations in a gene called interferon regulatory factor 6 (IRF6). Approximately 70 percent of people with VWS have an IRF6 mutation. When researchers compared the DNA of affected family members with the DNA of healthy family members, they discovered another gene—grainyheadlike 3 (GRHL3)—that was mutated only in the affected family members. They found that the same gene was altered in seven additional families with VWS in which no IRF6 mutations had been found. To further investigate the role of GRHL3 in oral abnormalities, researchers at six laboratories studied human mutations of this gene in zebra fish and mouse models. They found that mouse embryos that did not have the GRHL3 gene could not form proper palates and were born with clefts. They also found that GRHL3 encodes a transcription factor that is regulated by IRF6. The authors concluded that both genes are required for a proper formation of the palate and that they probably function in separate but convergent molecular pathways. “The discovery of a new gene, GRHL3, responsible for the most common of the syndromic forms of cleft lip and palate means that researchers or clinicians with collections of families or isolated cases with cleft lip and palate, syndromic or non-syndromic, now will be able to look for mutations in this gene,” said lead author Myriam PeyrardJanvid, PhD, Department of Biosciences and Nutrition, Karolinska Institutet. “As it has been shown for IRF6, one or several polymorphisms
in GRHL3 might be found to be associated with increased risk of clefts in non-syndromic cases.” The Swedish Research Council and the National Institutes of Health funded this study. PROTEIN DETERS HEAD, NECK CANCER GROWTH, STUDY SHOWS
S
JADA 145(3)
cientists at the National Institute of Dental and Craniofacial Research found that blocking a certain protein inhibited the proliferation of head and neck squamous cell carcinoma, according to a study published in the February issue of Molecular Oncology. In an experiment involving tissue samples of hundreds of head and neck cancer patients, an NIDCR team led by Silvio Gutkind, PhD, chief of NIDCR’s Oral and Pharyngeal Cancer Branch, found that p38 kinase was active in most samples. They reported that the most malignant tissue samples had the highest activity of p38, and the least malignant samples had the lowest p38 activity. The normal oral tissue used as a control had no p38 activity. When researchers turned off p38 activity in human oral cancer cells and transplanted these cells into laboratory mice, they found that the oral cancer cells without p38 activity were smaller than those with p38 activity. In addition, turning off p38 activity lessened the growth of new
COMING IN APRIL
dHospital-based emergency department visits regarding dental conditions dUsing stereophotogrammetry technology to make intraoral digital impressions for implants dOral care behaviors after purging in women with bulimia Look for this and more in the April issue of JADA.
http://jada.ada.org
March 2014
235
NEWS
blood vessels, which cancers rely on for growth and the ability to spread to other parts of the body. In the next phase of the study, they tested SB203580—a drug that is known to block p38 activity. SB203580 reduced the growth of head and neck cancer cells in the laboratory. When the NIDCR team then used SB203580 to treat human head and neck cancers that had been transplanted into lab mice, they found that SB203580 made the cancers smaller. The next step, Dr. Gutkind says, is to test a new generation of drugs that inhibit p38.
236
JADA 145(3)
http://jada.ada.org
CORRECTIONS
I
n the February issue, the article “Fluoride Toothpaste Use for Young Children” by the American Dental Association (ADA) Council on Scientific Affairs (JADA 2014;145[2]:190-191) contained two errors. dIt should have contained an additional citation. The third sentence in the first paragraph—“To assess the effectiveness and safety of using fluoride toothpaste for young children, the Council recommended a systematic review of the evidence”— should have referenced the systematic review, which also appeared
March 2014
in the February issue: “Fluoride Toothpaste Efficacy and Safety in Children Younger Than 6 Years: A Systematic Review,” by J. Timothy Wright, DDS, MS, and colleagues (JADA 2014;145[2]:182-189). dThe biographical information for one of the authors was incomplete. Clifford W. Whall, PhD, is the interim senior director, ADA Council on Scientific Affairs, and the director, Acceptance Program, ADA Council on Scientific Affairs. JADA regrets the errors. Q Compiled by Amy E. Lund, senior editor.