Clinical correlation of calpain-1 and glypican-3 expression with gallbladder carcinoma

Deciphering the Role of Ca2+ Signalling in Cancer Metastasis: From the Bench to the Bedside

Metastatic cancer is one of the major causes of cancer-related mortalities. Metastasis is a complex, multi-process phenomenon, and a hallmark of cancer. Calcium (Ca2+) is a ubiquitous secondary messenger, and it has become evident that Ca2+ signalling plays a vital role in cancer. Ca2+ homeostasis is dysregulated in physiological processes related to tumour metastasis and progression-including cellular adhesion, epithelial-mesenchymal transition, cell migration, motility, and invasion. In this review, we looked at the role of intracellular and extracellular Ca2+ signalling pathways in processes that contribute to metastasis at the local level and also their effects on cancer metastasis globally, as well as at underlying molecular mechanisms and clinical applications. Spatiotemporal Ca2+ homeostasis, in terms of oscillations or waves, is crucial for hindering tumour progression and metastasis. They are a limited number of clinical trials investigating treating patients with advanced stages of various cancer types. Ca2+ signalling may serve as a novel hallmark of cancer due to the versatility of Ca2+ signals in cells, which suggests that the modulation of specific upstream/downstream targets may be a therapeutic approach to treat cancer, particularly in patients with metastatic cancers.

The Glypican-4 Gene Polymorphism rs1048369 and Susceptibility to Epstein-Barr Virus-Positive and -Negative Nasopharyngeal Carcinoma in Northern China

BACKGROUND

Gene polymorphism rs1048369 of glypican-4 (GPC4) gene has been reported to be significantly different between Epstein-Barr virus (EBV)-associated gastric carcinoma (GC) and EBV-negative GC. However, little is known about the polymorphism in nasopharyngeal carcinoma (NPC), which is a malignant tumor with a high prevalence of EBV.

OBJECTIVE

The distribution of GPC4 polymorphism rs1048369 was investigated in NPC patients, especially in those with EBV infection. The association between the polymorphism of GPC4 and the susceptibility to EBV-positive and EBV-negative NPC was also explored.

PATIENTS AND METHODS

The GPC4 gene polymorphism rs1048369 was detected in 143 cases of EBV-positive NPC and in 19 cases of EBV-negative NPC using polymerase chain reaction. One hundred and seven peripheral blood samples from healthy individuals were also measured as a control group.

RESULTS

The difference in genotype CC between EBV-positive NPC patients and healthy individuals was significant (χ2 = 15.273, p < 0.01). No significant difference was observed between EBV-positive and EBV-negative NPC cases. Between EBV-negative NPC cases and healthy individuals, there was no significant difference in GPC4 gene polymorphism in both genotypic and allelic frequencies.

CONCLUSIONS

The GPC4 gene polymorphism is associated with susceptibility to EBV-positive NPC. The CC genotype of GPC4 may represent a risk factor for NPC in Northern China.

High calpain-1 expression predicts a poor clinical outcome and contributes to tumor progression in pancreatic cancer patients

BACKGROUND

Pancreatic cancer (PC) is a highly aggressive and metastatic disease, with an elevated mortality rate. It is, therefore, crucial to assess factors affecting the prognosis of PC patients. Meanwhile, calpain-1 is associated with malignant tumor progression and metastasis. Thus, it is meaningful to evaluate the relationship between calpain-1 and PC.

MATERIALS AND METHODS

Calpain-1 protein expression was assessed by immunohistochemistry in 96 pancreatic cancer samples and paired adjacent non-cancerous specimens. In addition, calpain-1 protein levels were assessed in six PC cell lines by western blot (WB). Next, PC cells were transfected with calpain-1 siRNA, and silencing was confirmed by WB. Finally, cell proliferation, colony formation, migration and invasion assays, and cell apoptosis analysis were performed to examine the effects of calpain-1 knockdown on proliferation, growth, apoptosis, migration, and invasion in PC cells.

RESULTS

The results showed that calpain-1 was overexpressed in PC tissues and cells. Meanwhile, calpain-1 overexpression was associated with tumor site (P = 0.029), metastasis (P = 0.000), and TNM stage (P = 0.000), but showed no associations with histological grade (P = 0.396), age (P = 0.809), sex (P = 1.000), and lesion size (P = 0.679). The Kaplan-Meier method demonstrated that the low calpain-1 expression group had increased overall survival (OS) compared with patients expressing high calpain-1 levels (28.7 ± 4.1 vs. 17.0 ± 2.3 months) (P = 0.005). Besides, calpain-1 in PC cells was successfully silenced by liposome-mediated RNA interference, resulting in reduced cell growth, invasion, and metastasis in PC cells, with no effect on apoptosis.

CONCLUSION

The above findings suggest that calpain-1 should be considered a potential biomarker for PC prognosis and therapy.

Calpain-2 inhibitor treatment preferentially reduces tumor progression for human colon cancer cells expressing highest levels of this enzyme

Calpain-2 levels are higher in colorectal tumors resistant to chemotherapy and previous work showed calpain-2 inhibitor therapy reduced inflammation-driven colorectal cancer, but direct effects of the inhibitor on colon cancer cells themselves were not demonstrated. In the present study, five human colon cancer cell lines were directly treated with a calpain-2 inhibitor and results showed increased cell death in 4 of 5 cell lines and decreased anchorage-independent growth for all cell five lines. When tested for levels of calpain-2, three cell lines exhibited increasing levels of this enzyme: HCT15 (low), HCC2998 (medium), and HCT116 (significantly higher). This was consistent with gel shift assays showing that calpain-2 inhibitor reduced of NF-κB nuclear translocation most effectively in HCT116 cells. Ability of calpain-2 inhibitor to impede tumor progression in vivo was evaluated using intrarectal transplant of luciferase-expressing cells for these three cell lines. Results showed that calpain-2 inhibitor therapy reduced tumor growth and increased survival only in mice injected with HCT116 cells. These data suggest calpain-2 inhibitor treatment may be most effective on colorectal tumors expressing highest levels of calpain-2.

Fetal gut-like differentiation in gallbladder cancer

Adenocarcinomas showing fetal gut-like (enteroblastic) differentiation can arise in a variety of organs and are frequently accompanied by an elevated serum α-fetoprotein (AFP) level. However, no study has investigated fetal gut-like differentiation in gallbladder cancer in detail. Herein, we performed morphological and immunohistochemical analyses of fetal gut-like differentiation in 49 consecutive gallbladder cancer cases. The expression of Sal-like protein 4 (SALL4), an embryonic stem cell marker reported to represent fetal gut-like differentiation, as well as other oncofetal proteins, including glypican-3 (GPC3) and AFP, was assessed. We found 1 case of fetal gut-like adenocarcinoma that coexisted with conventional-type adenocarcinoma. The fetal gut-like adenocarcinoma component revealed diffuse immunoreactivity for SALL4 and partial positivity for AFP, whereas the conventional-type adenocarcinoma component was negative. We also found 2 poorly differentiated adenocarcinomas with hepatoid morphology and 1 clear cell carcinoma, none of which showed SALL4 positivity. In other conventional-type adenocarcinomas, focal immunoreactivity for SALL4 and GPC3 was occasionally observed. The overall positivity rates for SALL4 and GPC3 were 12.2% (6/49) and 16.3% (8/49), respectively. SALL4 and GPC3 expression was not associated with clinicopathological factors, including T category, lymphovascular invasion, and lymph node metastases. In conclusion, fetal gut-like adenocarcinoma was found in 2% of our gallbladder cancer series. We conclude that fetal gut-like adenocarcinoma is a distinct histological subtype of gallbladder cancer, characterized by SALL4 expression.

Calpain-1 Expression in Triple-Negative Breast Cancer: A Potential Prognostic Factor Independent of the Proliferative/Apoptotic Index

Triple-negative breast cancer (TNBC) is an aggressive type of breast cancer in which calpain system plays an important role in its cellular processes including apoptosis and proliferation. Although such roles have been assessed in tumor pathogenesis, the correlation of its expression to the proliferating/apoptotic index has not been studied yet. Immunohistochemical staining of calpain-1 was performed on paraffin-embedded tissues to correlate its expression with clinicopathological variables and outcome. The proliferation activity was determined by calculating the percentage of cells expressing the Ki-67 antigen. The apoptotic index was assessed morphologically and biochemically using Haematoxylin & Eosin method and Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay, respectively. Calpain-1 was significantly expressed in TNBC tissues varying from low to high with a significant correlation to lymph node status but not with the other clinicopathological variables, suggesting its role as a prognostic factor. In addition, a positive correlation was found between both apoptotic counts assays (P < 0.001, r = 0.547) as well as with proliferation (P = 0.045). Calpain-1 expression had no significant correlation with either proliferation (P = 0.29) or apoptotic indices (P = 0.071 and P = 0.100). Determining calpain-1 expression may provide relevant prognostic value for TNBC cancer patients.