The Expression of Stem Cell Marker LGR5 and Its Coexpression with Β-Catenin in Sporadic Colorectal Carcinoma and Adenoma: A Comparative Immunohistochemical Study

Background: LGR5 is one of the most important stem cell markers for colorectal cancer (CRC), as it potentiates Wnt/Β-catenin signaling. The well-characterized deregulation of Wnt/Β-catenin signaling that occurs during adenoma/carcinoma sequence in CRC renders LGR5 a hopeful therapeutic target. We assessed the immunohistochemical expression of LGR5 and Β-catenin in normal colonic and tumorous lesions with a clinicopathological correlation. Methods: Tissue blocks and clinical data of 50 selected cases were included: 8 from normal mucosa, 12 cases of adenoma, and 30 cases of CRC, where sections were cut and re-examined and the immunohistochemical technique was conducted using anti-LGR5 and anti-Β-catenin to measure the staining density. Results: There was no expression of LGR5 in normal mucosa compared to samples of adenoma and CRC samples. The association analysis showed that CRC specimens were more likely to have strong LGR5 and Β-catenin expressions than the other two groups (p = 0.048 and p < 0.001, respectively). Specimens with high-grade dysplastic adenoma were more likely to express moderate-to-strong expression of LGR5 and Β-catenin (p = 0.013 and p = 0.036, respectively). In contrast, there were no statistically significant associations between LGR5 and Β-catenin expression with grade and stage. Conclusion: These results suggest and support the possible role of LGR5 as a potential marker of cancer stem cells in sporadic colorectal carcinogenesis in addition to a prognostic value for LGR5 and Β-catenin in adenomatous lesions according to immunohistochemical expression density. A potential therapeutic role of LGR5 in CRC is suggested for future studies based on its role in pathogenesis.

HER2/neu expression status of post BCG recurrent non-muscle-invasive bladder urothelial carcinomas in relation to their primary ones

BACKGROUND

Transurethral resection (TUR) followed by adjuvant therapy is still the treatment of choice of Non-Muscle-Invasive Bladder Urothelial Carcinoma (NMIBUC). However, recurrence is one of the most troublesome features of these lesions. Early second resection and adjuvant BCG therapy has been shown to improve the outcome.

OBJECTIVE

To evaluate the prognostic value of C-erbB-2 (HER2/neu) expression status in Non-Muscle-Invasive Bladder Urothelial Carcinoma cases, before and after intravesical Bacillus Calmette Guerin (BCG immunotherapy).

MATERIALS AND METHODS

HER2/neu expression was studied in 120 (Ta-T1) Non-Muscle-Invasive Urothelial Carcinoma cases. The expression was evaluated and compared to the expression after Bacillus Calmette Guerin (BCG) immunotherapy.

RESULTS

HER2/neu expression in low and high grade of the Non- Muscle-Invasive Urothelial Carcinoma was (38%) and (83%) respectively. The difference of the expression rates by tumor grade was statistically significant. In recurring lesions post BCG therapy, C-erbB-2 expression was markedly decreased (31.6%) when compared to its expression before therapy (65%).

CONCLUSIONS

The HER2/neu expression increased as the tumor grade rose. The reduction in expression following BCG treatment in Non-Invasive transitional cell carcinoma cases could reflect a reduction of the potential malignancy of the tumor.

Linear growth and neurodevelopmental outcome of children with congenital hypothyroidism detected by neonatal screening: A controlled study

INTRODUCTION

Different growth and neuro-developmental outcomes have been associated with different doses of thyroxine given to infants with congenital hypothyroidism (CH).

MATERIALS AND METHODS

We studied the longitudinal growth pattern and assessed the neurodevelopment of 45 children with CH(25 girls, 20 boys) diagnosed through the national screening program in Qatar, for 6 years or more to examine the effects of initial T4 dosage (50 μg/day) with adjustment of T4 dose to maintain serum free T4 concentrations within the upper quartile of normal range and thyroid stimulating hormone < 4 mIU/mLThe birth size of newborns with CH diagnosed through the screening program before January 2003, was recorded and their growth in weight and stature was monitored every 3 months for at least 6 years of life. The IQ of children was assessed between 3 and 6 years of age using The Wechsler Preschool and Primary Scale of Intelligence (WPPSI-III).

RESULTS

Birth weight, length, and head circumference of patients (3.21 ± 0.43 kg, 50.5 ± 3.21 cm and 34.1 ± 1.5 cm, respectively) did not differ than those for 10,560 normal newborns with normal thyroid function (3.19 ± 0.59 kg, 50.5 ± 2.2 cm and 34.2 ± 1.7 cm). During the first year CH children growth (25.8 ± 2.8 cm/year) was similar to those for normal infants (25.5 ± 0.75 cm/year). During the first 6 years, stature growth was normal in all children with CH versus Center for disease control and prevention (CDC) data. The mean height standard deviation score (HtSDS) of children with CH showed adjustment (± 0.5 SD) toward their mid-parental height SDS (MPHtSDS) only during the second year of life. The children's mean HtSDS was higher by an average of 0.4 SD between the 2(nd) and 7(th) year of life.

CONCLUSION

These data proved that effective screening and treatment completely assures normal neurodevelopment and linear growth in patients with CH. The data showed that their HtSDS slightly exceeds their MPHtSDS during childhood.

Influence of hydration on the dynamics of lysozyme

Quasielastic neutron and light-scattering techniques along with molecular dynamics simulations were employed to study the influence of hydration on the internal dynamics of lysozyme. We identified three major relaxation processes that contribute to the observed dynamics in the picosecond to nanosecond time range: 1), fluctuations of methyl groups; 2), fast picosecond relaxation; and 3), a slow relaxation process. A low-temperature onset of anharmonicity at T approximately 100 K is ascribed to methyl-group dynamics that is not sensitive to hydration level. The increase of hydration level seems to first increase the fast relaxation process and then activate the slow relaxation process at h approximately 0.2. The quasielastic scattering intensity associated with the slow process increases sharply with an increase of hydration to above h approximately 0.2. Activation of the slow process is responsible for the dynamical transition at T approximately 200 K. The dependence of the slow process on hydration correlates with the hydration dependence of the enzymatic activity of lysozyme, whereas the dependence of the fast process seems to correlate with the hydration dependence of hydrogen exchange of lysozyme.

Protein and solvent dynamics: How strongly are they coupled?

Analysis of Raman and neutron scattering spectra of lysozyme demonstrates that the protein dynamics follow the dynamics of the solvents glycerol and trehalose over the entire temperature range measured 100-350 K. The protein's fast conformational fluctuations and low-frequency vibrations and their temperature variations are very sensitive to behavior of the solvents. Our results give insight into previous counterintuitive observations that protein relaxation is stronger in solid trehalose than in liquid glycerol. They also provide insight into the effectiveness of glycerol as a biological cryopreservant.