Dependence of human cell survival and proliferation on the CASP3 prodomain.

Mechanisms that regulate cell survival and proliferation are important for both the development and homeostasis of normal tissue, and as well as for the emergence and expansion of malignant cell populations. Caspase-3 (CASP3) has long been recognized for its proteolytic role in orchestrating cell death-initiated pathways and related processes; however, whether CASP3 has other functions in mammalian cells that do not depend on its known catalytic activity have remained unknown. To investigate this possibility, we examined the biological and molecular consequences of reducing CASP3 levels in normal and transformed human cells using lentiviral-mediated short hairpin-based knockdown experiments in combination with approaches designed to test the potential rescue capability of different components of the CASP3 protein. The results showed that a ≥50% reduction in CASP3 levels rapidly and consistently arrested cell cycle progression and survival in all cell types tested. Mass spectrometry-based proteomic analyses and more specific flow cytometric measurements strongly implicated CASP3 as playing an essential role in regulating intracellular protein aggregate clearance. Intriguingly, the rescue experiments utilizing different forms of the CASP3 protein showed its prosurvival function and effective removal of protein aggregates did not require its well-known catalytic capability, and pinpointed the N-terminal prodomain of CASP3 as the exclusive component needed in a diversity of human cell types. These findings identify a new mechanism that regulates human cell survival and proliferation and thus expands the complexity of how these processes can be controlled. The graphical abstract illustrates the critical role of CASP3 for sustained proliferation and survival of human cells through the clearance of protein aggregates.

Remembering the legacy of Professor Mohammad Hashemi: a pioneer in molecular genetic studies in southeast Iran (1965-2019).

Professor Mohammad Hashemi was a clinical biochemist and cancer genetic scientist. He has been chair and head of Department of Clinical Biochemistry at Zahedan University of Medical Sciences, Zahedan, Iran. He has played an important role in the improvement of understanding of genetics of disease in southeast Iran. He was also a part of international team for the discovery of the role of calprotectin (S100A8/A9) in cancer biology via regulation of cell fate in tumor cells. He had over 300 peer-reviewed scientific publications and trained significant numbers of high quality personals (>40) in the field of biomedical sciences. His sudden death in 2019 shocked national and international scientific society but his scientific legacy will remain alive forever.

Paradoxical roles of caspase-3 in regulating cell survival, proliferation, and tumorigenesis.

Caspase-3 is a widely expressed member of a conserved family of proteins, generally recognized for their activated proteolytic roles in the execution of apoptosis in cells responding to specific extrinsic or intrinsic inducers of this mode of cell death. However, accumulating evidence indicates that caspase-3 also plays key roles in regulating the growth and homeostatic maintenance of both normal and malignant cells and tissues in multicellular organisms. Given that yeast possess an ancestral caspase-like gene suggests that the caspase-3 protein may have acquired different functions later during evolution to better meet the needs of more complex multicellular organisms, but without necessarily losing all of the functions of its ancestral yeast precursor. This review provides an update on what has been learned about these interesting dichotomous roles of caspase-3, their evolution, and their potential relevance to malignant as well as normal cell biology.

Relationship Between CASP9 and CASP10 Gene Polymorphisms and Cancer Susceptibility: Evidence from an Updated Meta-analysis.

Caspase-9 (CASP9) and caspase-10 (CASP10) polymorphisms were associated with human cancers; however, the results remain controversial. In this meta-analysis, we aimed to estimate the relationship among CASP9 (rs1052576, rs1052571, rs4645978, rs4645981, rs4645982, rs2308950) and CASP10 (rs13006529, rs13010627, rs3900115) polymorphisms and the overall risk of cancers. Relevant studies were obtained from Web of Science, MEDLINE, PubMed, Scopus, and Google scholar databases (updated January 1, 2021). Odds ratio (OR) and 95% confidence intervals (CIs) were measured to estimate the strength of association. Our meta-analysis included 40 studies. The rs4645981 significantly enhanced the risk of cancer under TT vs. CC (OR = 2.42), TC vs. CC (OR = 1.55), TT+ TC vs. CC (OR = 1.66), TT vs. TC + CC (OR = 1.91), and T vs. C (OR = 1.57) inheritance models. As for the rs1052571 variant, increased risk of cancer was observed under TT vs. CC (OR =1.22), TC vs. CC (OR = 1.17), and TT+ TC vs. CC (OR = 1.18) models. The stratified analysis showed a significant correlation between rs4645978 or rs4645981 polymorphisms and cancer risk, while in Asians rs4645978 conferred an increased risk of colorectal, lung, and prostate cancer. Both rs4645981 and rs1052576 polymorphisms were correlated with an enhanced risk of lung cancer. In conclusion, our meta-analysis suggested that CASP9 rs4645981 and rs1052571 polymorphisms are associated with overall cancer risk. More studies on larger populations are warranted to validate these associations.

Quantitative Assessment of the Effects of IL-1ß -511 C>T Variant on Breast Cancer Risk: An Updated Meta-Analysis of 3331 Cases and 3609 Controls.

OBJECTIVE: Growing evidence suggests that IL-1ß -511C>T, as a functional variant, affects the risk of developing breast cancer (BC); however, the results have not been conclusive. This meta-analysis was conducted to estimate the link between this variant and BC risk. METHODS: We retrieved available publications on IL-1ß -511C>T polymorphism by conducting a comprehensive literature search on the Web of Science, MEDLINE, PubMed, Scopus, and Google scholar databases (last search on February 25, 2020). RESULTS: The overall analysis indicates that IL-1ß -511C>T polymorphism conferred an increased risk of BC under a recessive TT vs CT+CC model by 1.14-fold and showed protection against BC under an overdominant CT vs TT+CC genetic contrast model (odds ratio = 0.84). Stratified analysis based on ethnicity revealed the protective effect of this single-nucleotide polymorphism against BC risk in Caucasian patients. CONCLUSION: Our data results provide a proof of concept for the association of IL-1ß -511C>T with BC risk. Larger, well-designed population-based studies are needed to confirm these findings.

Leukocyte Telomere Length Shortening, hTERT Genetic Polymorphisms and Risk of Childhood Acute Lymphoblastic Leukemia

Background: Telomeres are involved in chromosomal stability, cellular immortality and tumorigenesis. Human telomerase reverse transcriptase (TERT) is essential for the maintenance of telomere DNA length. Recently, a variable tandem-repeats polymorphism, MNS16A, located in the downstream region of the TERT gene, was reported to have an effect on TERT expression and telomerase activity. Previous studies have linked both relative telomere length (RTL) and TERT variants with cancer. Therefore, we evaluated associations between RTL, TERT gene polymorphisms (hTERT, rs2735940 C/T and MNS16A Ins/Del) and risk of childhood acute lymphoblastic leukemia (ALL) in an Iranian population. Methods: RTL was determined by a multiplex quantitative PCR-based method, and variants of the hTERT, rs2735940 C/T and MNS16A Ins/Del, were genotyped by amplification refractory mutation system PCR (ARMS-PCR), and PCR, respectively. Results: Our results indicated that RTL was shorter in ALL patients (1.53±0.12) compared to the control group (2.04±0.19) (P=0.029). However, no associations between hTERT gene variants or haplotypes and the risk of childhood ALL were observed (P>0.05). Also hTERT polymorphisms were not associated with RTL or patient clinicopathological characteristics, including age (P=0.304), sex (P=0.061) organomegally (P=0.212) CSF involvement (P=0.966) or response to treatment (P=0.58). Conclusions: We found that telomere attrition may be related to the pathogenesis of childhood ALL, irrespective to TERT variants.

Correction to: Lack of relationship between PTEN 32-bp and TP53 16-bp Ins/Del polymorphisms and chronic hepatitis B virus infection.

[This corrects the article DOI: 10.1007/s13337-017-0391-7.].

Association of Single Nucleotide Polymorphisms of the MDM4 Gene With the Susceptibility to Breast Cancer in a Southeast Iranian Population Sample.

INTRODUCTION: The murine double minute 4 (MDM4) protein is a negative regulator of p53, and its upregulation has been observed in many tumor types. Previous literature suggested that genetic variations in the MDM4 gene are associated with risk of different cancers. The objective of the present study was to examine the effect of 3 common genetic variants of MDM4, rs4245739 A>C, rs11801299 G>A, and rs1380576 C>G, on the risk of breast cancer (BC) in a southeast Iranian population sample. PATIENTS AND METHODS: A total of 265 BC patients and 221 healthy women were included in this case-control study. We used polymerase chain reaction (PCR)-restriction fragment length polymorphism and tetra amplification refractory mutation system-PCR methods for detection of MDM4 polymorphisms. RESULTS: Our findings showed that rs1380576 C>G was associated with a reduced risk of BC using co-dominant (GC vs. CC: odds ratio [OR], 0.54; 95% confidence interval [CI], 0.34-0.84; P = .006; and GG vs. CC: OR, 0.49; 95% CI, 0.26-0.94; P = .044), dominant (CG+GG vs. CC: OR, 0.54; 95% CI, 0.35-0.82; P = .004), and allele models (G vs. C: OR, 0.74; 95% CI, 0.57-0.96; P = .025). However, our study failed to show any relationship between rs4245739 A>C and rs11801299 G>A variants and BC risk (P > .05). We also found no significant association between MDM4 variants and clinical characteristics of BC patients (P > .05). CONCLUSION: Our findings proposed that the MDM4 rs1380576 C>G polymorphism was a protective factor for BC risk in our population. Additional studies with larger sample sizes and diverse ethnicities are required to confirm our findings.

4-bp insertion/deletion (rs3783553) polymorphism within the 3'UTR of IL1A contributes to the risk of prostate cancer in a sample of Iranian population.

Growing evidence demonstrated the presence of an association between IL1A rs3783553 polymorphism and the risk of various cancers. We aimed to evaluate whether the 4-bp insertion/deletion polymorphism (rs3783553) within the 3' untranslated region (3'UTRs) of IL1A was associated to the risk of prostate cancer (PCa) in a sample of Iranian population. A case-control study, including 150 prostate cancer patients and 155 healthy men, was done to examine the possible association between IL1A 4-bp ins/del polymorphism and PCa risk in a sample of southeast Iranian population. Mismatched polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was designed for genotyping the studied variant. Our findings showed that 4-bp ins/del polymorphism significantly increased the risk of PCa in codominant, recessive and allelic inheritance model. We also evaluated the association between the IL1A 4-bp ins/del polymorphism and clinicopathological characteristics of the patients, and found a significant association between 4-bp ins/del variant and stage, perineural invasion and surgical margin of tumor samples. Bioinformatics analysis revealed that the ins/del variant affected the IL1A mRNA stability leading to a structural shift in IL1A mRNA and has-miR-125a-3p hybrid. In conclusion, our findings proposed an association between IL1A 4-bp ins/del polymorphism and PCa risk. Additional studies with enlarged sample size and diverse ethnicities are required to validate our finding.

XPG Asp1104His, XRCC2 Rs3218536 A/G and RAD51 135G/C Gene Polymorphisms and Colorectal Cancer Risk: A Meta-Analysis

Background: DNA repair mechanisms are crucial for sustaining DNA integrity and preventing carcinogenesis. The xeroderma pigmentosum group G (XPG), X-ray repair cross complementing group 2 (XRCC2) and RAD51 are candidate genes for DNA repair pathways. Methods: We performed a meta-analysis of 26 studies that assessed the impact of XPG Asp1104His, XRCC2 rs3218536 A/G and RAD51 135G/C polymorphisms on colorectal cancer (CRC) risk. This study included 10288 CRC patients and 11885 controls, and odds ratio (OR) with its 95% confidence interval (CI) were used to calculate the strength of association. Results: The results of overall meta-analysis suggested an association between the XPG Asp1104His polymorphism and CRC susceptibility in allele (OR=1.06; 95% CI=1.01-1.12) and heterozygote model (OR=1.16; 95%CI=1.02-1.31). In the subgroup analysis based on ethnicity and source of control, we found significantly increased CRC cancer risk in Asians (OR=1.12, 95%CI=1.04-1.21) and in hospital-based (OR=1.22, 95%CI=1.08-1.38) populations. Moreover, the RAD51 135 G/C polymorphism increased the risk of CRC in total using allele (OR=1.21) and recessive models (OR=1.62). However, XRCC2 rs3218536 A/G was not associated with the risk of CRC in total or in subgroups. Conclusions: According to the results of our meta-analysis, the XPG Asp1104His and RAD51 135 G/C polymorphisms might influence colorectal cancer risk.

Association between TGFß1 polymorphisms and chronic hepatitis B infection in an Iranian population.

INTRODUCTION:: Transforming growth factor-beta 1 (TGFß1) is a potent suppressive cytokine that contributes to chronic hepatitis B (CHB) infection. Disparities in TGFß1 production among individuals have been attributed to TGFß1 genetic polymorphisms. We examined whether three putative polymorphisms in TGFß1[-509 C/T (rs1800469), +869 C/T (rs1800470), and +11929 C/T (rs1800472)]are associated with CHB infection in a South-Eastern Iranian population. METHODS:: In total, 341 subjects were recruited, including 178 patients with CHB and 163 healthy individuals as controls. Genotyping of the three TGFß1 SNPs was performed by tetra amplification refractory mutation system-PCR. RESULTS:: TheTGFß1 +869 TT vs.CC genotype in codominant (OR=0.445, p=0.012) and TT vs. TC+CC in the recessive (OR=0.439, p=0.003) model as well as the variant allele T vs. C(OR=0.714, p=0.038) were associated with lower CHB infection risk. However, the +11929 C/T polymorphism was associated with increased CHB risk, and the CT vs. CC genotype (OR=2.77, P=0.001) and T variant allele (OR=2.53, P=0.002) were risk factors for CHB. Furthermore, TTT (+869/-509/+11929) and CCC haplotypes were risk and protective factors for CHB, respectively. We found no significant association between viral DNA load and TGFß1 genotype or hepatic enzyme levels (p >0.05). CONCLUSIONS:: Results indicated that the TGFß1+869TT genotype and T allele were protective factors, whereas the +11929 CT genotype and T allele were risk factors for CHB infection.

KRAS Gene Polymorphisms and their Impact on Breast Cancer Risk in an Iranian Population

Single nucleotide polymorphisms (SNPs) in the let-7 miRNA binding site within the 3' untranslated region (3'UTR) of KRAS appear related to the risk of cancer. The present case-control study was conducted with 244 BC patients and 204 healthy women to examine whether KRAS polymorphisms (rs61764370 T/G and rs712 G/T) are associated with breast cancer (BC) risk in an Iranian population. The polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method was used for genotyping of KRAS SNPs. Our results showed that the rs61764370 TG genotype (OR= 3.73; 95% CI =1.38-10.08; P=0.007) as well as the G allele OR= 3.56; 95% CI =1.33-9.53; P=0.008, respectively) increased the risk of BC. However, the KRAS rs712 TT vs GG+GT genotype in a recessive model was associated with a reduced risk of BC (OR= 0.56; 95% CI =0.38-0.84; P=0.006). In addition, the rs712 T allele decreased the risk of BC compared with the G allele (OR=0.75, 95%CI=0.58-0.97, P=0.031). However, we found no relationship among KRAS SNPs and clinicopathological characteristics of BC patients (P>0.05). Taken together, the present study provided evidence of relationships between KRAS polymorphisms and BC risk in a southeast Iranian population. Additional studies using larger sample sizes and diverse ethnicities are now warranted.

Association between TGFß1 polymorphisms and chronic hepatitis B infection in an Iranian population

Abstract INTRODUCTION: Transforming growth factor-beta 1 (TGFβ1) is a potent suppressive cytokine that contributes to chronic hepatitis B (CHB) infection. Disparities in TGFβ1 production among individuals have been attributed to TGFβ1 genetic polymorphisms. We examined whether three putative polymorphisms in TGFβ1[-509 C/T (rs1800469), +869 C/T (rs1800470), and +11929 C/T (rs1800472)]are associated with CHB infection in a South-Eastern Iranian population. METHODS: In total, 341 subjects were recruited, including 178 patients with CHB and 163 healthy individuals as controls. Genotyping of the three TGFβ1 SNPs was performed by tetra amplification refractory mutation system-PCR. RESULTS: TheTGFβ1 +869 TT vs.CC genotype in codominant (OR=0.445, p=0.012) and TT vs. TC+CC in the recessive (OR=0.439, p=0.003) model as well as the variant allele T vs. C(OR=0.714, p=0.038) were associated with lower CHB infection risk. However, the +11929 C/T polymorphism was associated with increased CHB risk, and the CT vs. CC genotype (OR=2.77, P=0.001) and T variant allele (OR=2.53, P=0.002) were risk factors for CHB. Furthermore, TTT (+869/-509/+11929) and CCC haplotypes were risk and protective factors for CHB, respectively. We found no significant association between viral DNA load and TGFβ1 genotype or hepatic enzyme levels (p >0.05). CONCLUSIONS: Results indicated that the TGFβ1+869TT genotype and T allele were protective factors, whereas the +11929 CT genotype and T allele were risk factors for CHB infection.

Lack of relationship between PTEN 32-bp and TP53 16-bp Ins/Del polymorphisms and chronic hepatitis B virus infection.

TP53 and phosphate and tension homolog (PTEN) are two tumor suppressor genes that regulate cell proliferation, migration, and death. P53 and PTEN deficiency has been associated with hepatic fibrosis, a prominent pathological feature associated with chronic hepatitis B (CHB). The present study is aimed to assess the association of PTEN 32-bp Ins/Del (rs34421660) and TP53 16-bp Ins/Del polymorphisms with CHB infection susceptibility. A total of 411 subjects were recruited in this case-control study of 213 patients with CHB infection and 198 healthy individuals as controls. PTEN and TP53 deletions were detected by polymerase chain reaction method. We found no significant association between PTEN 32-bp Ins/Del polymorphism and the risk for CHB using either of codominant (Ins/Del vs. Ins/Ins: P = 0.427; Del/Del vs. Ins/Ins: P = 0.235), dominant (Ins/Del + Del/Del vs. Ins/Ins P = 0.343) or recessive genetic model (Del/Del vs. Ins/Ins + Ins/Del: P = 0.516). At allelic level although the PTEN Del variant allele was more common in CHB patients compared to controls (55 vs. 51), but the difference did not reach the statistical significant range (OR 0.87, P = 0.327). Similarly, no association was observed between TP53 16-bp Ins/Del and the risk for CHB infection at both genotype and allele levels (P > 0.05). In summary, our study demonstrated that the PTEN 32-bp and TP53 16-bp Ins/Del polymorphisms did not affect the risk of CHB infection in the Iranian population.