Frequency of Mismatch Repair Protein (MMRP) Deficiency among Young Jordanians Diagnosed with Colorectal Carcinoma (CRC).

PURPOSE: Microsatellite instability (MSI) caused by mismatch repair protein (MMRP) deficiency is detected in 15% of sporadic colorectal cancers (CRCs). Our aim is to investigate the frequency of MMRP deficiency in young CRC patients, using immunohistochemical analysis. METHODS: This study targeted cases of CRC at King Hussein Cancer Center from 2004 until 2012 in patients 45 years of age or younger at the time of diagnosis. Clinicopathological data was obtained from 155 patients' records. Immunohistochemistry for MLH1, MSH2, PMS2, and MSH6 proteins was performed on paraffin-embedded tissue containing carcinoma. RESULTS: The median age of patient at diagnosis was 38 years. A total of 29 (19%) cases showed deficient MMRP(dMMRP)expression. Loss of expression of PMS2 was seen in 17 cases, 12 cases of which showed loss of MLH1 expression. Loss of expression of MSH6 was seen in 10 cases, 9 of which showed loss of MSH2 expression. One case (3.4%) showed loss of all four MMR proteins, and another case (3.4%) showed loss of PMS2/MLH1 and MSH6. There was a significant association between abnormal MMR protein expression and tumor location proximal to splenic flexure (p value 0.000), pathologic features suggestive of microsatellite instability (p value 0.000), P53 negativity (p value 0.000), and stage (p value 0.02). Patients with dMMRP CRC appeared to have a significantly better overall survival compared to patients with proficient MMRP(pMMRP)(p value 0.02). Loss of MSH2/MSH6 was significantly associated with positive family history of cancer (p value = 0.020). CONCLUSIONS: The prevalence of dMMRP tumors in this age group appears to be similar to international literature. dMMRP tumors tends to be associated with earlier stages and better outcomes compared to pMMRP cases. dMMRP can serve as a biomarker for better prognosis. These results are of value in directing the clinical management of young patients with CRC.

Enhancing chemosensitivity of wild-type and drug-resistant MDA-MB-231 triple-negative breast cancer cell line to doxorubicin by silencing of STAT 3, Notch-1, and ß-catenin genes.

BACKGROUND/OBJECTIVE: The absence of receptors in triple-negative breast cancer limits therapeutic choices utilized in clinical management of the disease. Doxorubicin is an important member of therapeutic regimens that is hindered by emergence of resistance. The current work aim to investigate of therapeutic potential of single and combinations of siRNA molecules designed for silencing STAT 3, Notch-1, and ß-catenin genes in wild type and doxorubicin resistant MDA-MB-231 triple negative breast cancer cell line. METHODS: Doxorubicin resistant MDA-MB-231 cell line was developed and characterized for the expression of multidrug resistance-related genes, CD44/CD24 markers, inflammatory cytokines, and the expression of STAT 3, Notch-1, and ß-catenin targeted genes. Further, the effect of single and combinations of siRNA on cell viability and chemosensitivity of both wild type MDA-MB-231 cells (MDA-MB-231/WT) and doxorubicin resistant MDA-MB-231 cells (MDA-MB-231/DR250) were assessed by MTT assay. RESULTS: The IC50 of doxorubicin was 10-folds higher in MDA-MB-231/DR250 resistant cells compared to MDA-MB-231/WT control cells, 1.53 ± 0.24 µM compared to 0.16 ± 0.02 µM, respectively. The expression of targeted genes was higher in resistant cells compared to control cells, 3.6 ± 0.16 folds increase in ß-catenin, 2.7 ± 0.09 folds increase in Notch-1, and 1.8 ± 0.09 folds increase in STAT-3. Following treatment with siRNAs, there was a variable reduction in mRNA expression of each of the targeted genes compared to scrambled siRNA and a reduction in IC50 in both cell lines. The effect of a combination of three genes produced the largest reduction in IC50 in resistant cell line. CONCLUSION: Our study showed that the silencing of single and multiple genes involved in drug resistance and tumor progression by siRNA can enhance the chemosensitivity of cancer cells to conventional chemotherapy.

Hematologic Markers of Lung Metastasis in Stage IV Colorectal Cancer.

BACKGROUND: Many studies showed an association between absolute neutrophil count (ANC), absolute monocyte count (AMC), neutrophil-lymphocyte ratio (NLR), monocyte-lymphocyte ratio (MLR), and platelet-lymphocyte ratio (PLR) with poor overall survival (OS) in patients with cancer. However, only a few studies were conducted to further investigate this association in colorectal cancer (CRC). METHODS: Clinical data from 299 stage IV CRC patients treated at King Hussein Cancer Center from 2004 to 2012 have been retrospectively reviewed. We examined the association between ANC, AMC, MLR, PLR, and NLR with lung metastasis in stage IV CRC. Receiver Operating Characteristic (ROC) curve analysis was operated to determine the optimal NLR cutoff value. Univariate and multivariate analysis were performed. RESULTS: The ROC value of 3.4 was determined as the cutoff value of NLR to study the association. Univariate and multivariate analysis showed that patients with high baseline NLR (≥ 3.4) had more baseline lung metastasis than patients with low NLR (< 3.4) (p = 0.0001, p = 0.0151, respectively). Also, baseline NLR correlated significantly with the presence of lymphovascular invasion (p = 0.001). In patients with no baseline lung metastasis, high post-treatment NLR was associated with consequent development of lung metastasis (p = 0.0227). Other markers including ANC, AMC, MLR, and PLR were significantly associated with lung metastasis at time of diagnosis (p = 0.0006, p = 0.0006, p = 0.0187, and p = 0.001, respectively). CONCLUSION: Results are suggesting that different hematologic markers obtained from a cheap test (CBC) could potentially be used to predict the likelihood of lung metastasis in stage IV CRC. Prospective studies are needed to further assess the immune cells' role in tumor metastasis promotion.