Paraffin-embedded Cancer Tissue Samples Research Articles

RNAscope in situ hybridization confirms mRNA integrity in formalin-fixed, paraffin-embedded cancer tissue samples.

Immunohistochemistry remains the overwhelming technique of choice for test biomarker evaluation in both clinical or research settings when using formalin-fixed, paraffin embedded tissue sections. However, validations can be complex with significant issues about specificity, sensitivity and reproducibility. The vast array of commercially available antibodies from many vendors may also lead to non-standard approaches which are difficult to cross-reference. In contrast mRNA detection, by in situ hybridization (ISH) with sequence specific probes, offers a realistic alternative, with less validation steps and more stringent and reproducible assessment criteria. In the present study mRNA ISH was evaluated in prospectively and retrospectively collected FFPE samples within a cancer biobank setting. Three positive control probes, POLR2A, PPIB and UBC were applied to FFPE sections from a range of tumour types in FFPE whole-face (prospective collection) or TMA (retrospective collection) formats and evaluated semi-quantitatively and by image analysis. Results indicate that mRNA can be robustly evaluated by ISH in prospectively and retrospectively collected tissue samples. Furthermore, for 2 important test biomarkers, PD-L1 and c-MET, we show that mRNA ISH is a technology that can be applied with confidence in the majority of tissue samples because there are quantifiable levels of control probes indicating overall mRNA integrity.

Expression of KIF18A in gastric cancer and its association with prognosis

To explore the expression of KIF18A gene protein in gastric cancer tissues and its association with the prognosis of patients. Twenty fresh paired gastric cancer specimens and adjacent normal mucosa(at least 5 cm from the edge of tumor) from 20 gastric cancer patients undergoing operation in Department of General Surgery at the First Affiliated Hosptial of Anhui Medical University between March 2015 and July 2015 were collected. Real-time PCR was used to examine KIF18A mRNA expression in above specimens. Meanwhile, paraffin embedded cancer tissue samples from 129 gastric cancer patients undergoing operation and 23 samples of randomly selected normal gastric tissue(adjacent non-cancer tissue) were collected to establish the microarray. Immunohistochemistry method was applied to detect the KIF18A protein expression in the microarray after confirmation by pathologists. Association of KIF18A expression with clinicopathological features in gastric cancer patients was evaluated. Cox proportional hazard model was used to identify prognostic risk factors. Among 20 fresh paired gastric cancer specimens, mRNA expression of KIF18A in 16 specimens was obviously lower than that in adjacent normal tissues. The positive rate of KIF18A protein expression in gastric cancer tissues was significantly lower than that in normal gastric tissues in microarray[45.0%(58/129) vs. 69.6%(16/23), P=0.041]. KIF18A protein expression was significantly associated with invasion depth (P=0.008) and TNM staging (P=0.032). The median overall survival of all the 129 patients was 44.0(95% CI: 39.78-49.24) months. The three-year survival rates of patients with high and low KIF18A expression were 67.2% and 36.6% respectively(P=0.020). Cox regression analysis showed that KIF18A expression was an independent protective factor of the prognosis of gastric cancer patients (HR=0.570, 95% CI:0.335 to 0.970). KIF18A expression is down-regulated in gastric cancer tissue, which may play a critical role in gastric cancer carcinogenesis. Lower expression of KIF18A is associated with poor prognosis of gastric cancer patients. KIF18A may be a potential prognostic marker of gastric cancer.

Overexpression of lactate dehydrogenase-A in human intrahepatic cholangiocarcinoma: its implication for treatment

BackgroundPrevious studies have shown that lactate dehydrogenase-A (LDH-A) is strongly expressed in several malignancies, that LDH-A expression is associated with poor prognosis, and that LDH-A inhibition severely diminishes tumorigenicity. However, little is known about the implications of LDH-A expression in intrahepatic cholangiocarcinoma. The purpose of this study was to investigate the expression of LDH-A and to clarify its effect on intrahepatic cholangiocarcinoma.MethodsWe studied the expression of LDH-A in tissue samples from patients with intrahepatic cholangiocarcinoma (n = 54) using the ultrasensitive surfactant protein (S-P) immunohistochemical method. We then inhibited LDH-A using small hairpin RNA (shRNA) in the cholangiocarcinoma cell line HuCCT-1 in vitro to study the role it plays in promoting growth and escaping apoptosis.ResultsWe report that LDH-A was overexpressed in 52 of 54 (96%) paraffin-embedded cancer tissue samples and 0 of 54 para-carcinoma tissue samples. Reduction of LDH-A by RNA interference (RNAi) inhibited cell growth and induced apoptosis in HuCCT-1 cells. This result correlated with the elevation of cytoplasmic reactive oxygen species (ROS) levels.ConclusionsLDH-A expression is closely correlated with histopathological variables of intrahepatic cholangiocarcinoma, indicating that LDH-A may serve as a new treatment target.

High level of ezrin expression in colorectal cancer tissues is closely related to tumor malignancy

To investigate the ezrin expression in normal colorectal mucosa and colorectal cancer tissues, and study the correlation between ezrin expression in colorectal cancer tissues and tumor invasion and metastasis. Eighty paraffin-embedded cancer tissue samples were selected from primary colorectal adenocarcinoma. Twenty-eight patients had well-differentiated, 22 had moderately differentiated and 30 had poorly differentiated adenocarcinoma. Forty-five patients and 35 patients had lymph node metastasis. Forty-five patients were of Dukes A to B stage, and 35 were of C to D stage. Another 22 paraffin-embedded tissue blocks of normal colorectal epithelium (> 5 cm away from the edge of the tumor) were selected as the control group. All patients with colorectal cancer were treated surgically and diagnosed histologically, without preoperative chemotherapy or radiotherapy. The immunohistochemistry was used to detect the ezrin expression in paraffin-embedded normal colorectal mucosa tissues and colorectal cancer tissue samples. Ezrin expression in colorectal cancer was significantly higher than in normal colorectal mucosa (75.00% vs 9.09%, P < 0.01), and there was a close relationship between ezrin expression and the degree of tumor differentiation, lymph node metastasis and Dukes stage (88.46% vs 50.00%, P < 0.01; 94.28% vs 51.11%, P < 0.01; 94.28% vs 51.11%, P < 0.01). Ezrin expression is obviously higher in colorectal cancer tissues than in normal colorectal mucosa tissues, and the high level of ezrin expression is closely related to the colorectal cancer invasion and metastasis process.

Association of cyclooxygenase-2 expression with prognosis of stage T1 grade 3 bladder cancer

Objectives To determine whether the expression of cyclooxygenase-2 (COX-2) has prognostic significance in Stage T1G3 transitional cell carcinoma of the bladder, the most unfavorable subgroup in terms of recurrence and disease progression. Methods Thirty-seven consecutive patients with initial T1G3 transitional cell carcinoma, who had undergone complete transurethral resection, followed by 6 weeks of intravesical instillation of bacille Calmette-Guérin (BCG), and with at least 1 year of follow-up, were enrolled in the study. Paraffin-embedded cancer tissue samples were immunohistochemically stained for COX-2, and possible correlations with clinicopathologic features, such as age, shape and multiplicity of tumor, recurrence, and progression were examined. Results The median follow-up was 27 months (range 12 to 67). Sixteen patients (43.2%) experienced recurrence and 6 (16.2%) had progression defined as muscle invasion. Of 37 specimens, 16 (43.2%) stained positive for COX-2, defined as 5% or greater of positively stained cancer cells. COX-2 expression was statistically significant in predicting both recurrence ( P = 0.0493) and disease progression ( P = 0.0272). Patient age and the shape and multiplicity of tumors were not significantly predictive of recurrence or progression. Conclusions In a pathologically homogeneous group of T1G3 transitional cell carcinoma of the bladder, the expression of COX-2 correlated with recurrence and progression. Thus, patients with COX-2 positive superficial bladder cancer may need to be followed up more vigorously. Additional studies on the mechanistic implications of COX-2 with respect to recurrence and progression and the possible application of a COX-2 inhibitor to prevent recurrence and progression of superficial bladder cancer are warranted.