|
Genetic Study Identifies Four Main Types of Breast Cancer |
 |
|
In recent years, scientists have gradually come to appreciate that breast cancer triggered by myriad genetic and lifestyle factors. However, the latest study published in the journal Nature indicates that the mechanism of breast cancer may be slightly simpler than the researchers thought. Then, the researchers collected 510 tumors from 507 patients with breast cancer and aimed to sequence tumor genomes from dozens of different cancers so as to better understand the development and treatment of tumor. Finally, they found that there is presence of 30,626 mutations in these cancer cells, which were divided into four groups. The researchers find that women at higher risk of developing breast cancer are also more vulnerable to getting ovarian cancer.In two related subtypes, luminal A and luminal B, the scientists found that while the mutation rate in these cancers was lower, genetic aberrations occurred in a larger number of genes, suggesting that a more complex interaction of abnormal genes contribute to these types of breast cancer. Teasing apart such connections will be critical for improving treatment for women with these mutations. The researchers spare great efforts to figure out the genetic roots of these different types of breast cancer, which is an important first step down the road to individualized medicine. It might also be possible that some of the newly developed targeted drugs created for other cancers may work on breast cancers too. If that’s the case, then repurposing such existing targeted therapies may also improve breast-cancer outcomes. |
|
|
No Higher Risk for Women with Breast Cancer Genes in the Family |
|
|
Generally speaking, the women with a family history of breast cancer have a higher risk of developing breast cancer. Nevertheless, the findings of a study pointed out, if one don’t have the mutated genes, the risks of breast cancer will not increase significantly. The genetic mutations, known as BRCA1 and BRCA2, can increase a woman’s risk of developing breast cancer five-fold. Compared with women who had BRCA1 or BRCA2, 12% of women in the general population will develop breast cancer. Previously, a study found that women who didn’t have the mutations, but had first-degree relatives who did, were at a two- to five-times increased risk of breast cancer. This findings prompted many women to consider preventive measures, such as frequent biopsy of breast lumps and prophylactic mastectomy. However, the result of the new study goes against these previous findings. Totally 3,000 families with breast cancer were involved in the study, including nearly 300 who had the BRCA1 or BRCA2 mutations. On the whole, the new findings suggest that women in families with BRCA carriers don’t have to screen themselves for breast cancer more often than the general population with routine examinations on condition that they don’t have other risk factors. Furthermore, the genetic testing can also be applied to determine whether they are at higher risk of developing breast cancer for that it can provide the women with their real risk level. |
|
Novel Role of the NEDD9 Gene in Early Stages of Breast Cancer |
|
|
Breast cancer is the second leading cause of cancer deaths among women in the United States. Recently, researchers found a protein called NEDD9 was associated with the invasion and metastasis of tumor in a variety of cancers. The findings was published in the journal Oncogene on January 14, 2013, which may further provide personalized treatment strategies for women with breast cancer on the basis of the levels of NEDD9 in their tumors. Several years ago, the investigators have related NEDD9 with metastasis of tumor at later stages. Furthermore, this study shows how important NEDD9 can be for the initiation of tumors in breast cancer. In this study, the researchers mated mice without the NEDD9 gene to mice engineered to develop HER2+ mammary tumors and unexpectedly found that these mice were largely resistant to tumor formation. Only 18% of the mice developed mammary tumors, compared with 80% of mice that had a functional NEDD9 gene. Importantly, compared with mice that had a functional NEDD9 gene, mice lacking NEDD9 showed a significant reduction in progenitor cell populations in the mammary gland. Progenitor cells from NEDD9-null mice were less likely to form three-dimensional mammospheres in culture, but proliferated at the same rate as cells from control mice. These findings suggest that these types of drugs would more effectively control breast cancer tumors with low levels of NEDD9.Furthermore, the investigators try to figure out the mechanisms by which NEDD9 controls the formation of tumor and determine whether NEDD9 plays a similar role in early stages of other types of cancer. |
|
Researchers find a gene that promotes drug-resistance |
|
|
Recently, researchers identified a gene which may be the target for overcoming drug-resistance during the course of treatment. This finding can not only improve prognostic and diagnostic tools for evaluating cancer and monitoring patients' response to treatment but also could help develop new therapies aimed at eliminating drug-resistant cancer cells. As we all know, drug-resistance is a common phenomenon in clinic. Particularly, for many metastatic cancers, once the drug-resistance develops, the patients may don’t respond to the chemotherapy and the prognostic outcomes are bad. Initially, the investigators devoted themselves to identifying the genes associated with the development of drug-resistance in multiple myeloma. Then, they identified a gene named NEK2 which is closely related with increased drug-resistance, faster growth of cancer cells and poorer survival for patients. The paper was published in the journal of Cancer Cell. According to the results of the research, the investigators established the relationship between high expression of the NEK2 gene and poor outcome in myeloma. Furthermore, they also found that there is presence of the relationship in common cancers. Now, the team is developing compounds to inhibit the expression of NEK2 and hope that these compounds may overcome drug-resistance in cancer cells. The leader of the team pointed out that over-expression of NEK2 in cancer cells significantly enhances the activity of drug efflux proteins to pump chemotherapy drugs out of cells and finally contributes to drug-resistance. Although development and clinical testing of such drugs for is not imminent, the drugs may come into use within the next several years. Apart from that, this approach can also be applied in monitoring the patients’ reaction to the treatment. As a whole, this finding plays an important role in the prognosis and treatment of cancer. |
|
Chemotherapy may Trigger Tumors’ Resistance |
|
|
As we all know, 90% of patients with metastatic cancers may develop drug-resistance after several courses of chemotherapy and some researchers may figure out the actual reason. Recently, a study published in the journal Nature Medicine reported that an excess of a protein called WNT16B may promote the growths of cancer cells and furthermore the surrounding tissue will be affected. Fibroblast cells, which are the main component of connective tissue, can promote the healing of wounds and produce collagen to maintain cells’ structure. However, if fibroblast cells are doused during the course of chemotherapy, it damages their DNA causing them to overproduce WNT16B. This finding is completely out of the investigators’ expectations. Previously, WNT16B has been implicated in the development of normal cells and it hasn’t been identified as a cause of drug-resistance until now. Generally speaking, chemotherapy is administrated in cycles intermittently so that the patients can recover from the toxic effects of the drug. Nevertheless, it does not always eradicate all tumors. In some cases, high dosage of chemotherapy would not only kill the cancer cells but also the normal cells in the patients’ body. The leader of this new study pointed out that sometimes chemotherapy can stimulate surrounding healthy immune cells to fight against tumors. However, the investigators find that the normal cells surrounding the tumor can also help the tumor to become resistant to chemotherapy. Therefore, they hope that they can counter NT16B’s effect and improve the effectiveness of chemotherapy. With the development of medicine, some targeting therapies for cancer emerged in recent years, such as cell-based immunotherapy. Cell-based immunotherapy is a kind of biological therapy for cancer and it exploits the patients’ immune system to fight against cancer cells without damaging the normal cells. Furthermore, it can improve the patients’ quality of life and prolong their survival time form the long term. As a whole, cell-based immunotherapy is a good alternative therapy for cancer. |
|
|
|
|
<< Start < Prev 1 2 3 4 5 6 7 8 9 10 Next > End >>
|
|
Page 1 of 11 |
