What are MMTV PyMT mice?
The MMTV-PyMT (mouse mammary tumor virus-polyoma middle tumor-antigen) mouse model of breast cancer is widely used and well characterized. MMTV-PyMT mice develop spontaneous mammary tumors that closely resemble the progression and morphology of human breast cancers [12-14].
How are the transgenic mice used in cancer?
These mice provide valuable clues about the biological function of a normal gene. In translational cancer research, this represents a powerful tool in assessing the potential validity of targeted therapy because the targets can be precisely inactivated in the setting of a developing or developed tumor.
What is Luminal B breast cancer definition?
Advertisement. Luminal B-like breast cancer is estrogen-receptor-positive and HER2-positive and has any level of Ki-67 and may be progesterone receptor-positive or progesterone receptor-negative. Luminal B cancers tend to grow faster than luminal A cancers and have a slightly worse prognosis.
Why are transgenic mice used?
Transgenic mice can also be used to study gene function or to generate models for human genetic disease, provided that the desired effect can be observed when the transgene is expressed in the presence of the multitude of host genes. In other words, dominant gain-of-function genetic alterations can be studied.
What is the difference between luminal A and luminal B?
Luminal B subtypes had the highest percentage (54.9%) of involvement of lymph nodes when compared to the other four subtypes. The Luminal B subtype had a higher percentage (51.4%) of involvement of lymph nodes than did Luminal A (10.7%). The chi-square test also shows the difference to be significant (P < 0.05).
Is Luminal B breast cancer aggressive?
Luminal B breast cancer is defined by aggressive clinical behavior and has a prognosis similar to that of non-luminal cancers (including the HER2−enriched and base-like subtypes) [7].
Is a knockout mouse transgenic?
Transgenic mice, in which the gene is depleted or silenced to cause a loss of gene function, are called knockout mice.
Can luminal A be Grade 2?
Luminal A tumors tend to be: Estrogen receptor-positive (ER-positive) HER2 receptor-negative (HER2-negative) Tumor grade 1 or 2.
Is Luminal B breast cancer curable?
Moreover, the two ER + breast cancer subtypes, luminal A and luminal B, are linked with a good prognosis and excellent long-term survival (approximately 80%–85% 5-year survival), whereas the ER negative subtypes (HER2 + and basal-like) are challenging to manage and are linked with poor prognosis (approximately 50%–60% …
What is transgenic and knockout mice?
Transgenic mice is genetically modified mouse that has its genome altered through the use of genetic engineering techniques, while knockout mouse have inactivated, or “knocked out,” an existing gene by replacing it or disrupting it with an artificial piece of DNA.
What is knockout transgenic?
This approach involves generating transgenic mice, in which a foreign gene is integrated into an animal’s genetic material, as well as knockout or knock-in mice, in which candidate genes are either inactivated or altered, resulting in a lack of or change in protein expression.
What is luminal A vs B?
Luminal A subtype was defined as being ER positive, HER2 negative, and Ki67 low (<14% cells positive) and luminal B subtype as being ER positive, HER2 negative, and Ki67 high (≥14% cells positive). Luminal tumors were also subgrouped into risk categories based on the PR and TP53 status.
What is luminal A vs luminal B?
Luminal A breast cancers are likely to benefit from hormone therapy and may also benefit from chemotherapy. Group 2 (luminal B). This type includes tumors that are ER positive, PR negative and HER2 positive.
Is Ki-67 the same as Oncotype?
Background: Ki-67 is a marker of proliferating cells. The recurrence score based on the 21-gene breast cancer assay also called Oncotype Dx provides prognostic and predictive information for recurrence in early stage breast cancer patients.
What is high Ki-67?
Conclusions: High Ki67 expression is associated with ER negativity, Her2 positivity, higher grade and axillary lymph node involvement in breast cancers. The level of Ki67 expression is a prognostic factor predicting relapse-free and overall survival in breast cancer patients.
Why are MMTV-pyvt transgenic mice more susceptible to mammary cancer?
These mice have high penetrance of early onset of mammary cancer compared to other mammary tumor models. Male carriers also develop mammary tumors with a later age of onset. MMTV-PyVT transgenic mice express the Polyoma Virus middle T antigen under the direction of the mouse mammary tumor virus promoter/enhancer.
What is the pathophysiology of metastatic pulmonary metastasis in MMTV-PyMT mice?
In the pre-metastatic lung of MMTV-PyMT mice, an influx of neutrophils (CD11b+Ly6G+) occurs and their numbers continue to increase during the metastatic progression [ 97 ]. Animals with depleted neutrophils display a reduction in spontaneous pulmonary metastasis [ 97 ].
What is another name for MMTV PyMT?
Also Known As: MMTV-PyMT. Hemizygous MMTV-PyMT females develop palpable mammary tumors which metastasize to the lung. These mice have high penetrance of early onset of mammary cancer compared to other mammary tumor models.
Is the polyomavirus inducible in transgenic mice?
Inducible and coupled expression of the polyomavirus middle T antigen and Cre recombinase in transgenic mice: an in vivo model for synthetic viability in mammary tumour progression. Breast Cancer Res. 2014;16:R11.. doi: 10.1186/bcr3603.