In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

Q: Context: This study investigated whether deletion of the alpha1A-adrenoceptor gene influences contractile responses of mouse prostate to noradrenaline. Responses of mouse prostate to noradrenaline are known to be mediated by alpha1L-adrenoceptors, which are thought to be a functional phenotype of alpha1A-adrenoceptor.', 'Prostate tissues from alpha1A-adrenoceptor knockout mice which were homozygous (alpha1A -/-) and heterozygous (alpha1A +/-) for the disrupted alpha1A-adrenoceptor gene, as well as wild-type (alpha1A +/+) littermates were mounted in glass-isolated organ baths. Electrical field stimulation of nerves and exogenous application of noradrenaline were used to investigate the effects of alpha1A-adrenoceptor disruption on prostate contractility.', 'Frequency-response curves to electrical field stimulation (0.5 ms pulse duration, 60 V, 0.1-20 Hz) yielded frequency-dependent contractions. At frequencies of 10 and 20 Hz, prostates from alpha1A -/- mice elicited an approximately 30% decreased response compared with prostates from alpha(1A)+/+ mice. Prazosin (0.3 muM) attenuated responses to electrical field stimulation in prostates from alpha1A +/+ and alpha1A +/- mice but not from alpha1A -/- mice. Increasing concentrations of exogenously administered noradrenaline (10 nM-1 mM) produced mean concentration-response curves in prostates from alpha1A +/+ and alpha1A +/- mice, which were not different. Maximum responses to noradrenaline were decreased by approximately 80% in prostates from alpha1A -/- mice compared with alpha1A +/+ mice. Prazosin attenuated responses to noradrenaline in all genotypes.\Question: Is the alpha1A-adrenoceptor gene required for the alpha1L-adrenoceptor-mediated response in isolated preparations of the mouse prostate?

A: alpha1L-Adrenoceptor-mediated responses in mouse prostate are abolished in alpha1A -/- mice, demonstrating that the alpha1A-adrenoceptor gene is essential to the manifestation of the prostatic alpha1L-adrenoceptor phenotype. This implies that alpha1L-adrenoceptors are indeed a functional phenotype of alpha1A-adrenoceptor.
****
Q: Context: Nonviral vectors based on polyethylenimine (PEI) usually contain an excess of PEI that is not complexed to DNA. Since unbound PEI contributes to cellular and systemic toxicity, purification of polyplexes from unbound PEI is desirable.', 'Size exclusion chromatography (SEC) was used to purify PEI polyplexes of free PEI. Transfection properties of purified polyplexes and the effect of free PEI on gene delivery were studied in vitro and in vivo after systemic application into mice.', 'SEC did not change the size and zeta-potential of polyplexes. Independent of the amount of PEI used for complex formation, purified PEI polyplexes had the same final PEI nitrogen/DNA phosphate ratio of 2.5. Notably, purified PEI polyplexes demonstrated low cellular and systemic toxicity. High transfection efficiency was achieved with purified polyplexes at high DNA concentrations (8-15 microg/ml). At low DNA concentrations (2-4 microg/ml) gene transfer with purified particles was less efficient than with polyplexes containing free PEI both in vitro and in vivo. Mechanistic studies showed that free PEI partly blocked cellular association of DNA complexes but was essential for the following intracellular gene delivery. Adding free PEI to cells treated with purified particles with a delay of up to 4 h resulted in significantly enhanced transfection efficiency compared with non-purified particles or purified particles without free PEI.\Question: Does purification of polyethylenimine polyplexes highlight the role of free polycations in gene transfer?

A: This study presents an efficient method to remove free PEI from PEI polyplexes by SEC. Our results from transfection experiments demonstrate that free PEI substantially contributes to efficient gene expression but also mediates toxic effects in a dose-dependent manner. Purified polyplexes without free PEI have to be applied at increased concentrations to achieve high transfection levels, but exhibit a greatly improved toxicity profile.
****
Q: Context: beta-Catenin has been shown to play an important role in the formation of hair follicle-related tumors, including pilomatricomas. Several investigators have shown that beta-catenin gene mutation is observed in pilomatricomas. However, the relationship between the pattern of beta-catenin localization in the cell and beta-catenin gene mutation is still controversial.', 'This work was performed to determine the frequency of beta-catenin nuclear localization in pilomatricoma, the relationship between the pattern of beta-catenin localization and beta-catenin mutation, and the involvement of APC mutation.', 'Typical 32 pilomatricomas were examined for beta-catenin expression by immunostaining. Genomic DNA was extracted, amplified and sequenced from 23 pilomaticomas with nuclear beta-catenin staining and 4 pilomaticomas without nuclear beta-catenin staining. Mutations of beta-catenin gene were confirmed by subcloning assay and restriction endonuclease assay.', 'Using immunostaining, we found that 81% (26/32) of pilomatricomas displayed nuclear beta-catenin staining in basophilic cells. Sequence analysis revealed that 61% (14/23) contained mutations in exon 3 of beta-catenin. However, no mutations were detected in 4 pilomaticomas without beta-catenin nuclear staining. Detected mutations were adjacent to or abolished well-known regulatory phosphorylation sites of beta-catenin. APC gene mutations were not detected in 27 pilomatricomas with/without beta-catenin nuclear staining.\Question: Are beta-Catenin mutation and its nuclear localization confirmed to be frequent causes of Wnt signaling pathway activation in pilomatricomas?

A:
These results confirmed that beta-catenin mutation and its nuclear localization are frequent causes of Wnt signaling pathway activation and suggested that beta-catenin activation mutations contribute to tumorigenesis of pilomatricomas.
****