Role of the VEGF in virus-associated cancers

The role of numerous risk factors, including consumption of alcohol, smoking, having diet high in fat and sugar and many other items, on caner progression cannot be denied. Viral diseases are one these factors, and they can initiate some signalling pathways causing cancer. For example, they can be effective on providing oxygen and nutrients by inducing VEGF expression. In this review article, we summarised the mechanisms of angiogenesis and VEGF expression in cancerous tissues which are infected with oncoviruses (Epstein-Barr virus, Human papillomavirus infection, Human T-lymphotropic virus, Kaposi's sarcoma-associated herpesvirus, Hepatitis B and hepatitis C virus).

The prevalence of varicella zoster virus, herpes simplex virus type 2, and human papillomavirus in breast cancerous tissues and their adjacent ones in Iran

Background

Breast cancer is the second type of cancer in the world. Some internal and external risk factors, especially infection diseases, can progress breast cancer. As the relation between varicella zoster virus (VZV), human papillomavirus (HPV), herpes simplex virus type 2 (HSV-2), and breast cancer has not been understood, it was attempting to find the effect of these viruses and breast cancer in this study.

Materials and Methods

We collected 40 breast cancer and 50 healthy adjacent tissues from Taleghani and Imam Hossein Hospital, Tehran, Iran, in 3 years starting in 2017. After extracting DNA from breast tissues, multiplex polymerase chain reaction (PCR), nested PCR, and PCR were done to analyze the prevalence of HSV-2, VZV, and HPV.

Results

Our results showed that HPV may be one of the important causes of breast cancer. Nested PCR illustrated nine breast cancerous tissues (mean age: 43) and three healthy adjacent ones (mean age: 41) were infected by HPV. Phylogenetic analysis illustrated that all of the infected HPV cancerous and healthy tissues were HPV 18 (except two healthy samples infected with HPV 6). Nevertheless, there were not any infected tissues by HSV-2 and VZV.

Conclusion

It seems that HPV virus type 18 can have high prevalence in breast cancerous tissues in comparison with healthy adjacent ones, and it is likely to have an effect on breast cancer progression. However, the opposite trend is true for HSV-2 and VZV as we did not find any differences between different kinds of breast tissues.

Low presence of papillomavirus and its lack of correlation with clinicopathological factors in breast cancer: a case control study

Background and Objectives

Breast cancer is currently the most commonly diagnosed neoplasm in women worldwide. There is evidence that human papillomavirus (HPV) infection may play a key role in breast cancer aggressiveness, but results are conflicting across studies. The aim of this study was to investigate the presence of the HPV viral genome in benign and malignant breast tissue samples and its clinicopathological characteristics of cancer.

Materials and Methods

In this case-control study, 100 formalin-fixed paraffin-embedded (FFPE) of breast cancer and 100 blocks of non-cancerous breast tissue were selected as a control group from the pathology department of Imam Khomeini Hospital in Ahvaz from 2020-2022. The presence of HPV was detected using nested PCR including MY09/11 primers and sequencing were performed for virus genotyping.

Results

The present study enrolled 100 subjects each in two cancer and control groups with a mean age of 52.81±13.23 and 35.77±11.65, respectively. The risk of cancer in HPV-infected patients is almost 5 times higher than in HPV-negative individuals, it is not statistically significant (OR =4.99, 95% CI 0.35 to 72.15, p=0.238). The prevalence of HPV in the cancer and control groups was 7% and 1%, respectively and HPVs detected in two groups were of the HPV 16 genotype. Although the chance of ER and PR expression, lymphvascular involvement, perineural invasion, and higher tumor grade was higher in HPV-positive subjects than in HPV-negative subjects, this was not statistically significant (OR>1, p>0.05).

Conclusion

Based on studies reporting the existence of sequences of different high-risk HPV types (oncogenes) in breast cancer tissues, this study confirmed the hypothesis of a possible infectious cause in the development of breast cancer. So far, however, the results have been controversial and inconclusive. Further studies with large sample sizes are needed to demonstrate the link between HPV and breast cancer.

Human Respiratory Syncytial Virus and Coronavirus Rates in Iranian Elderly Patients More than 60 Years Old with Acute Respiratory Symptoms

Background

Scientists have believed that a number of risk factors, especially viral infectious agents, can be related to respiratory diseases. Due to the pandemics in 2019, Human Respiratory Syncytial Virus and Coronavirus have attracted the attention of different kinds of research. In this study, we attempted to evaluate the prevalence of these viruses.

Materials and Methods

After extracting the RNA and DNA of these viruses, molecular tests were employed to report the rate of them in patients suffering from respiratory symptoms.

Results

Our results demonstrated that 31 samples were COVID-19 positive. Furthermore, two cases had Respiratory syncytial virus (RSV) subgroup A infections. However, no cases showed a coinfection of both viruses.

Conclusions

It seems that during the pandemic of COVID-19, RSV should not be ignored as it can be responsible for the respiratory syndrome.

Detection of HSV-1, HSV-2 and VZV Isolated from Cerebrospinal Fluid Samples of Children Suspected to Encephalitis

Background

Encephalitis is an uncommon, serious brain infection that can cause fatality among children. The cause of most encephalitis remained unknown, yet viruses are the most well-known infectious agents that cause encephalitis. This study aimed to determine varicella-zoster virus (VZV) and herpes simplex virus type 1, 2 (HSV1/2) among individuals who are under 5 years of age in Iran.

Materials and Methods

In this study, 149 cerebrospinal fluid samples of suspected patients of encephalitis were analyzed with some symptoms, such as seizure, fever, nausea loss of consciousness, and dizziness from Mofid Children's Hospital in Tehran, Iran. Then, the molecular evaluation of samples was performed using multiplex Polymerase Chain Reaction (PCR) for detecting HSV1/2 and VZV.

Results

The mean age of the patients was 1.8 years. Also, 63.4% of children were male and 36.6% were female. Out of 149 tested samples, 11 (7.3%) showed the viral DNA for one of the herpes viruses (7.3%). Nine samples were HSV1 positive (6.0%) and two samples were VZV positive (1.3%). Fever and vomiting were the most frequent symptoms. The mean ± standard deviation (SD) WBC and counts in cerebrospinal fluid (CSF)-positive samples, and all included samples were 298.8 ± 552.7 cells/μL and 131.1 ± 474.6 cells/μL, respectively.

Conclusions

Although viral encephalitis is considered a threat to children's health, with accurate diagnosis and appropriate antiviral drugs, death and neurological complications in children can be prevented.

The Evaluation of HERV-K np9, rec, gag Expression in Isolated Human Peripheral Blood Mononuclear Cell (PBMC) of Gastric and Colon Cancer

Background

In the current age of diagnostic approaches in cancer, countless efforts have been allocated to identify novel and efficient biomarkers to detect cancer in its early stages. We focused on evaluating the correlation between the progression of gastrointestinal cancer, a leading cause of cancer death worldwide, and human endogenous retrovirus (HERV).

Materials and Methods

In this study, we conducted a study on the peripheral blood mononuclear cells (PBMC) gathered from gastric and colon cancer patients. We focused on HERV-K rec, np9, gag expression analysis by quantitative real-time PCR, after extraction of RNA and synthesizing cDNA.

Results

Unlike np9 whose expression increased significantly in the colon and gastric cancers, the mRNA level of the rec gene declined in both cancers. Moreover, our data illustrated that the over-expression of the gag gene was only observed in colon cancerous cells rather than gastric malignancy.

Conclusions

Overall, given the correlation between the expression level of HERV-associated genes and gastrointestinal cancer, our study suggests that these genes could be considered beneficial markers for cancer diagnosis. However, researchers should conduct studies in future articles on whether these genes can be employed as biomarkers in gastrointestinal cancer.

Deregulation of the Hippo Signaling Pathway in Virus-Associated Cancer

"Hippo signaling has been recognized as a newly identified tumor suppressor signaling pathway that can regulate cellular processes including regeneration, cell death, differentiation, and development. Its dysregulation through overexpression of YAP (Yes-associated protein) and TAZ (PDZ-binding motif) as two main oncogenic factors of the Hippo pathway has a crucial role in several cancers. Because of the limited prognosis and therapeutic targets, further understanding of molecular pathways involved in tumorigenesis is one of the interesting issues in studies. Here, we demonstrated that some viruses, through dysregulation of the Hippo signaling pathway can be implicated in transformation, metastasis, and chemotherapeutic drug resistance in virus-related cancer and also help processes involved in the pathogenesis of viral infection such as persistence "

Prevalence of Human Papillomavirus and Co-Infection with Epstein-Barr Virus in Oral and Oropharyngeal Squamous Cell Carcinomas

BACKGROUND

Head and neck squamous cell carcinoma is one of the most important malignancies, worldwide. Oncogenic viruses, such as human papilloma virus (HPV) and Epstein-Barr virus (EBV), are linked to these cancers and studies suggest a possible interaction between HPV and EBV during co-infections to promote oncogenesis. Nonetheless, these reports are controversial and demand more investigations in this regard. The present work to assessed the prevalence of HPV and co-infection with EBV in oral and oropharyngeal squamous cell carcinomas.

METHODS

Formalin-fixed paraffin-embedded tissues were collected from 166 archived oral and oropharyngeal squamous cell carcinoma samples from Ahvaz Imam Khomeini hospital, Ahvaz, Iran, from March 2013 and December 2019. Nested-PCR was used to detect the viruses and type-specific PCR/nested-PCR and sequencing were performed for virus genotyping.

RESULTS

Out of the 166 specimens, 84.33% and 16.42% were from oral cavity and oropharynx, respectively; of which, 32 cases (19.3%) were HPV-positive (16.42% of oral cavity and 34.6% of oropharynx). HPV was detected in 36.36%, 25%, and 16.42% of base of tongue, tonsil, and oral tongue tumors, respectively. HPV was more associated with well differentiated tumors (24;18.04%) in compared to moderately and poorly differentiated ones. Regarding HPV-16 genotyping, 7 (21.8%) out of the 32 samples were found to be HPV-16 (4/26 (15.38%) for oropharynx and 3/140 (2.14%) for oral cavity). Moreover, 90 samples were evaluated for EBV infection and co-infection; of which, 4 (4.4%) subjects tested positive for EBV, including two cases with HPV co-infection. All the positive cases were EBV type B, from oral cavity, and histologically well differentiated.

CONCLUSIONS

HPV was more associated with oropharyngeal cancer. This association has been linked to various factors such as repeated oral and oropharyngeal exposure to HPV due to change in patterns of sexual behaviors; a phenomenon that may demand routine HPV vaccination.

Analysing the HERV-K env, np9, rec and gag expression in cervical tissues

Cervical cancer is considered to be the fourth common cancer. It is assumed that numerous risk factors, especially infectious ones, can have a detrimental effect on cervical cancer. In this study, we evaluated the expression of Herv-K env, np9, rec and gag in cervical tissues. After RNA extraction and cDNA sensitizing of 12 cervical cancer tissues and CIN3, 51 CIN1,2 and 18 normal ones, Herv-K env, np9, rec and gag were assessed using quantitative real-time PCR analysis. There was a decrease in the level of HERV-K env expression in cervical cancer and CIN 1-3 in compression with normal tissues. Cervical cancer and CIN3 indicated the most increase in expression. Meanwhile, we observed an increase in gag and rec expression in CIN 1,2; although cervical cancer and CIN 3 had a decrease in rec and gag expression, we did not report any changes in np expression. In conclusion, given the relationship between HERV-associated genes and cervical cancer, our study suggests that these genes can be useful for cancer diagnosis. However, further investigations are needed to provide a better perspective about the effectiveness of these genes in the diagnostic strategies of gastrointestinal cancer. These results are just an observation that could open a wider investigation to test the correlation between the expression of these genes and cervical cancer.

Detection of Major Human Herpesviruses in Iranian Patients with Suspected Encephalitis Using Multiplex Polymerase Chain Reaction

BACKGROUND

The Herpesviridae family plays a significant etiological role in central nervous system viral infections during primary infection or reactivation from a latent form. Early detection is crucial because prescribing some antivirals can prevent severe side effects or life-threatening conditions.

METHODS

In this study, 251 CSF specimens were collected from patients with clinical suspicion of viral encephalitis in Pars Hospital, Tehran, Iran. DNA was extracted, and a multiplex PCR was designed to investigate the presence of herpes simplex virus-1, herpes simplex virus-2, varicella zoster virus, Epstein-Barr virus, and cytomegalovirus.

RESULTS

Overall, 59 cases of the 251 CSF samples were positive for multiplex PCR (23.5%). The most frequent positive findings were EBV and HSV, with a prevalence of 10.3% and 8.7% (5.5% HSV-1 and 3.1% HSV-2), respectively. Four co-infections were also seen in this study.

CONCLUSIONS

This multiplex PCR assay detects simultaneously different herpesviruses in CSF samples of patients with suspected encephalitis in 2 rounds of PCR amplification; therefore, it is a reliable and cost-saving diagnostic method for evaluating patients infected with herpesvirus with neurological disorders.

Detection of extensively drug-resistant and hypervirulent Klebsiella pneumoniae ST15, ST147, ST377 and ST442 in Iran

In this study, we focused on the emergence of extensively drug-resistant (XDR), pandrug-resistant (PDR), and hypervirulent Klebsiella pneumoniae (hvKP) in Iran. During 2018 to 2020 a total of 52 K. pneumoniae isolates were collected from different clinical specimens. The hvKP isolates were identified by PCR amplification of virulence and capsular serotype-specific genes. Hypermucoviscous K. pneumoniae (hmKP) were identified by string test. Carbapenem-resistant hvKP (CR-hvKP), multidrug-resistant hvKP (MDR-hvKP), extensively drug-resistant hvKP (XDR-hvKP), and pandrug-resistant hvKP (PDR-hvKP) were determined by disc diffusion method, Carba-NP test and PCR method. XDR-hvKP isolates were typed by multilocus sequence typing (MLST). Among all K. pneumoniae isolates 14 (26.9%) were identified as hvKP and 78.6% (11/14) of them were hmKP however, none of the classic K. pneumoniae (cKP) isolates were hmKP. The predominant capsular serotype of hvKP was K2 (42.85%) followed by K1 (35.71%). The prevalence of MDR-hvKP, XDR-hvKP and PDR-hvKP isolates were 6 (42.9%), 5 (35.7%) and 1 (7.1%), respectively. ESBL production was found in 85.7% of hvKP isolates and most of them carried bla TEM gene (78.6%) and 6 isolates (42.9%) were CR-hvKP. Among hvKP isolates, 1 (7.1%), 2 (14.3%), 3 (21.4%), 8 (28.6%), and 11 (78.6%) carried bla NDM-6, bla OXA-48, bla CTX-M, bla SHV, and bla TEM genes, respectively. According to MLST analysis, 2, 1, 1, and 1 XDR-hvKP isolates belonged to ST15, ST377, ST442, and ST147, respectively. The occurrence of such isolates is deeply concerning due to the combination of hypervirulence and extensively drug-resistance or pandrug-resistance.

Detection of Enterovirus, Herpes Simplex, Varicella Zoster, Epstein-Barr and Cytomegalovirus in cerebrospinal fluid in meningitis patients in Iran

Background

Despite medical advances, central nervous system (CNS) diseases put a pressure on the health care system. A number of risk factors, especially infectious agents can accelerate the progression of meningitis. As viruses probably account for most cases of meningitis, the diagnosis of them can reduce antibiotic prescriptions. Among various types of infectious diseases, the relationship between two important virus families, including Picornaviridae and Herpesviridae, and meningitis has attracted attraction.

Methods

In this study, one hundred and two samples were collected from patients who experienced symptoms, such as the loss of consciousness, seizures, muscle weakness, fever, headache, rash, and severe dementia, between November 2018 and September 2019. After RNA and DNA extraction, the prevalence of Enterovirus (EV), Cytomegalovirus (CMV), Epstein–Barr virus (EBV), Herpes simplex virus type 1 (HSV‐1), Herpes simplex virus type 2 (HSV‐2), and Varicella zoster virus (VZV) was evaluated using PCR, multiplex PCR, and nested PCR.

Results

Results indicated that there were two VZV DNA‐positive specimens, while six and five samples were infected with HSV‐1 and EBV, respectively.

Conclusion

We reported that the prevalence of EBV, HSV‐1, and VZV in patients, suffering from meningitis cannot be ignored; however, further investigation is needed.

Proliferative Effect of FadA Recombinant Protein from Fusobacterium nucleatum on SW480 Colorectal Cancer Cell Line

BACKGROUND AND AIM

Colorectal Cancer (CRC) is one of the most frequent cancers diagnosed in both men and women worldwide. Fusobacterium nucleatum adhesin A (FadA) has an important potential factor in the development or progression of CRC. The aim of the present study was to evaluate the proliferative effect of recombinant FadA on SW480 colorectal cancer cell line.

MATERIALS AND METHODS

The recombinant pET21(b)-fadA plasmid was synthesized and transformed into competent E.coli DH5α. In the next step, induction and expression of recombinant FadA were carried out in E. coli BL21 (DE3) competent cells. Expression and purification of protein were successfully done and it was analyzed and confirmed by SDS-PAGE and western blotting. The proliferative effect of purified FadA on SW480 CRC cell line was evaluated using MTT assay and cell counting methods.

RESULTS

Visualization of the specific band isolated from the linear plasmid on the agarose gel confirmed the presence of the desired gene. After electrophoresis and Coomassie blue staining, the protein of interest with an approximate molecular weight of 13KDa was detected. The MTT assay, similar to cell counting methods, revealed that FadA dose and time-dependently promoted SW480 cell growth and proliferation in 24, 48 and 72 hours.

CONCLUSION

The results showed that FadA stimulates proliferation of SW480 colorectal cancer cell line with a dose and time-dependent manner.

The evaluation of Human papilloma virus and human herpes viruses (EBV, CMV, VZV HSV-1 and HSV-2) in semen samples

There are a number of risk factors, especially viral diseases, which can lead to infertility. Among the various viral infections, much attention has been given to the role of the Papillomaviridae and Herpesviridae. After collecting 82 semen samples (37 teratospermia, 2 asthenozoospermia, 2 oligoasthenospermia, 1 oligospermia, 6 asthenoteratospermia and 34 normal semen samples), and washing them, the DNA from both freshly ejaculated spermatozoon and washed spermatozoa was extracted. Subsequently, the prevalence of EBV, CMV, HSV-1, HSV-2, VZV and HPV was evaluated using Multiplex PCR and Nested PCR. In this study, 1 normal and 5 abnormal semen samples were infected with HSV-1 (1 normal, 4 teratospermia and 1 oligoasthenospermia). In addition, there were 2 VZV-positive samples (both were teratozoospermia). Nested PCR indicated that 1 asthenozoospermia, 1 asthenoteratospermia, 3 teratospermia and 4 normal samples were HPV positive (including 8 HPV-18 and 1 HPV-33). Among 9 HPV-positive subjects, 3 samples were negative after washing the infected samples. The prevalence of EBV, CMV, VZV, HSV-1 and HSV-2 remained unchanged prior to and after washing. Maybe sperm washing can be useful to eliminate HPV infection from semen samples, but further investigation is required because of the small number of samples.

Comparison of Snail1, ZEB1, E-Cadherin Expression Levels in HPV-Induced Cervical Cancer

Background:

Molecular profiling techniques are the rapid detection of biomarkers in the human papillomavirus (HPV) infected cells. We aimed to measure the expression level of three cell factors including Snail1, ZEB-1, and E-cadherin in cervical cancer (CC), precancerous and healthy samples, simultaneously, to find potential biomarkers.

Methods:

The expression level of the mentioned cell factors were investigated in 72 CC patients, precancerous patients, and healthy controls by using Real-Time PCR.

Results:

The results demonstrated a significant reduction in the expression level of E-cadherin in cancer and precancerous cases than that in healthy cases; whereas the expression level of ZEB-1 and Snail1 were upregulated in cancer and precancerous samples. The receiver operating characteristic (ROC) analyses shows the highest AUC value emerged for Snail1: 1(95% CI: 1-1) in comparing CC and healthy groups with a sensitivity of 100.0 % and specificity of 100.0%.

Conclusion:

The molecular biomarker Snail1 may be helpful to early diagnosis and prognosis of CC in the HPV-infected human populations. Considering the increased expression level of Snail1 in cancer and precancerous tissue compared to healthy tissue as well as the area under the ROC curve, Snail1 can be used for early detection of CC.

Prevalence of HSV, Varicella-Zoster, CMV, EBV and HPV in the oral cavity and the larynx carcinoma in Iran

Introduction: Viral diseases can have roles in oral cavity and larynx carcinoma. However, the relationship between HPV, herpetic infection and these cancers is not clear. Materials & methods: DNA of tissues from oral and larynx carcinoma was extracted and the presence of HPV, HSV-1, HSV-2, EBV, CMV and Varicella Zoster virus was detected. Results: We detected five HSV-1 in oral cavity cancer and two HSV-1 in larynx carcinoma. Also, four and two HPV-positive in oral cavity and larynx carcinoma were found, respectively. There were five HPV type 18 and one HPV type 31. None of our samples were infected with EBV, CMV, HSV-2 and Varicella Zoster virus. Conclusion: A higher prevalence of HPV and HSV-1 in cancerous tissues in comparison with normal ones was detected.

Detection of human papillomavirus genotypes, herpes simplex, varicella zoster and cytomegalovirus in breast cancer patients

BACKGROUND

The role of viruses as a cause of breast cancer (BC) has been significantly investigated in recent years. Human papillomavirus (HPV) has been detected in invasive breast carcinomas, while most studies have only focused on the detection of viral DNA, we aimed to examine the prevalence and genotypes of HPV among Iranian BC patients. We also examined the presence of herpes simplex-1 (HSV-1), herpes simplex-2 (HSV-2), varicella zoster virus (VZV), and cytomegalovirus (CMV) in these samples.

METHODS

We collected and analyzed 70 Formalin-Fixed Paraffin-Embedded (FFPE) blocks including 59 BC samples, and 11 benign breast lesions as control from Iranian patients using nested PCR. Real-time PCR utilized as a confirming test to nested PCR findings. Genotyping of HPV positive samples was performed, the samples were also subjected to a multiplex PCR to detect HSV-1, HSV-2, VZV, and CMV in BC.

RESULTS

Papillomavirus DNA was present in 7 of 59 BC samples (11.8%); while none was detected in control samples. The most prevalent type was HPV18, followed by HPV 6. All HPV positive patients had high tumor grades (II/ III) with a histologic diagnosis of ductal carcinoma. The patient age range was 33 to 73 years with a median of 51 years. Most of HPV positive patients had low levels of education. HPV16 was not detected. Also, 5 of 59 BC specimens (8.47%), were positive for HSV-1. But none of the samples were positive for HSV-2, VZV, and CMV.

CONCLUSIONS

Our results suggest a carcinogenesis role for High-risk HPV (HPV18) in breast tumors. Our findings of HSV-1 and low-risk HPV (HPV6) in BCs may propose a cancer-causing role for them. Further large-scale studies are warranted to assess the significance of our findings.

The role of viruses in adenocarcinoma development

Cancer is a leading public health issue that accounts for million deaths around the world every year. Human cancers contain over 100 types, which are categorized into different groups. Adenocarcinoma is one of those categories of cancer that begins from the glans and involves various tissues such as lung, esophagus, pancreas, prostate and colorectal. A range of risk factors has been identified for the development and progression of adenocarcinomas. One of these risk factors are viruses that serves special mechanisms to affect important host cell factors and tumorigenic pathways, contributing in development and promotion of adenocarcinomas. Here, we summarized the main viruses and their mechanisms implicated in the course of various adenocarcinomas development.

In silico analysis of a chimeric fusion protein as a new vaccine candidate against Clostridium perfringens type A and Clostridium septicum alpha toxins

In silico analysis is the most important approach to understand protein structure and functions, and the most important problem for designing and producing a fusion construct is producing large amounts of functional protein. Clostridium perfringens type A and Clostridium septicum produce alpha (plc) and alpha toxins respectively. C. perfringens can cause gas gangrene and gastrointestinal diseases. C. septicum can cause traumatic and non-traumatic gas gangrene. The aim of current research was in silico analysis of a chimeric fusion protein against C. perfringens type A and C. septicum alpha toxins. Firstly, the chimeric fusion gene was designed according to nucleotide sequences of C. perfringens type A alpha (KY584046.1) and C. septicum alpha (JN793989.2) toxin genes and then its fusion protein is constructed by amino acid sequences of C. perfringens type A and C. septicum alpha toxins. Secondly, online software was used to determine prediction of secondary and tertiary structures and physicochemical characteristics of the fusion protein. Finally, the validation of the fusion protein was confirmed by Rampage and proSA program. The designed fusion protein has 777 amino acids in length. TASSER server and physicochemical parameters are showed: C-score = − 2.68 and molecular weight = 87.9 KD respectively. Rampage and proSA software revealed the fusion protein is valid. Deposited accession number for the sequence of the fusion gene in the GenBank is MK908396. The designed fusion protein is valid and functional. Thus, the fusion gene could be used for clone and expression in a proper prokaryotic cell and also as a recombinant vaccine candidate.

Cyclin-dependent kinases and CDK inhibitors in virus-associated cancers

The role of several risk factors, such as pollution, consumption of alcohol, age, sex and obesity in cancer progression is undeniable. Human malignancies are mainly characterized by deregulation of cyclin-dependent kinases (CDK) and cyclin inhibitor kinases (CIK) activities. Viruses express some onco-proteins which could interfere with CDK and CIKs function, and induce some signals to replicate their genome into host's cells. By reviewing some studies about the function of CDK and CIKs in cells infected with oncoviruses, such as HPV, HTLV, HERV, EBV, KSHV, HBV and HCV, we reviewed the mechanisms of different onco-proteins which could deregulate the cell cycle proteins.

Epidemiology of herpes simplex and varicella zoster virus in cerebrospinal fluid of patients suffering from meningitis in Iran

From the early 18th century that “meningitis” outbreak was firstly recorded in Geneva, it is one of the alarming health problems worldwide. Different infectious risk factors may contribute to the progression of meningitis. Herpes simplex virus (HSV) and Varicella-zoster virus (VZV) are just some noticeable risk factors among many involved in the progression of this disease. In this study, 415 meningitis suspected patients were recruited with some symptoms, such as fever, headache, nausea or vomiting, seizure, rash, dizziness from four different hospitals of Iran and molecular examinations of samples were performed by using specific primers of HSV½ and VZV via real-time PCR. Out of 415 included patient 41 (9.8 %) were VZV and six (1.4 %) cases were HSV ½ positive. Fever was the most frequent symptom by 315 (76 %) of patients with median temperature of 38 °C in all included patients. The median WBS counts of CSF in VZV positive, HSV½ positive, and all included cases were 1567 × 10⁶ /L, 1257 × 10⁶ /L, and 766 × 10⁶ /L (range 0-21200), respectively. In conclusion, as the rate of VZV infection was high among children patients and it was associated with the absence of vaccination program for chickenpox in Iran, we suggested that VZV is one of the plausible hallmarks in meningitis.

Evaluating the expression level of miR-9-5p and miR-192-5p in gastrointestinal cancer: introducing novel screening biomarkers for patients

OBJECTIVE

It has been indicated that there is a tight association between cancer and different factors, such as environment and genetics, including aberrantly expressed microRNAs. The crucial role of microRNAs in the regulation of diverse signaling pathways in gastrointestinal cancer has been established in several studies. In this study, we aimed to evaluate the expression of microRNA-9 and -192 in colon and gastric cancers. After extracting the RNA from tissues and serum samples of patients, suffering from colon and gastric cancer, cDNA was synthesized. Then by performing quantitative real-time PCR, we evaluated the expression level of miR-9-5p and miR-192-5p in collected samples.

RESULTS

Unlike to colon cancer in which the expression level of miR-9-5p remained unchanged, the relative expression of this miRNA decreased remarkably in gastric cancer (with P value < 0.05), in comparison with normal adjacent tissues. In agreement with this finding, we also found that the expression level of miR-192-5p was decreased in gastric cancer tissues, compared to normal gastric tissue. Given the reduction in the expression level of miR-9-5p and miR-192-5p in gastric cancer, it could be postulated to consider these miRNAs as promising diagnostic biomarkers.

Prevalence of Epstein-Barr virus (EBV) in Iranian Breast Carcinoma Patients

Introduction:

Breast cancer (BC) is the most common malignancy affecting females worldwide. Various risk factors play a role in the developing of BC. Infectious agents like viruses have been proposed for this cancer and Epstein-Barr virus (EBV) is a widely researched candidate virus. This study detects the presence of EBV-DNA in breast cancer patients.

Methods:

The study was conducted on 59 formalin-fixed paraffin-embedded (FFPE) tissue blocks samples of women with breast carcinoma and 11 non-neoplastic breast controls. The DNA was extracted for all the samples. Then detection of EBNA1 EBV was done by polymerase chain reaction (PCR).

Results:

EBV was detected in 6.7% (4/59) of patients while all breast control samples were negative. All patients with positive EBV-DNA were high tumor grades (II, and III). Also, they had a low level of educations.

Conclusions:

According to our findings, it can be suggested that EBV may have a potential role in breast cancer development. However, this study provides substantial but not conclusive evidence for the involvement of viruses in BC disease development. Therefore, future investigations are needed to elucidate the exact role of EBV in breast cancer.

Prevalence of Human Papilloma Virus in Patients With Colorectal Cancer: A Systematic Review and Meta-analysis

Background: Human papillomavirus (HPV) is considered as one of the most common carcinogenic viruses in humans throughout the world and is mostly associated with gynecologic malignancies. However, it is also one of the environmental factors that is involved in colorectal cancer (CRC). Objective: A meta-analysis was performed to investigate the prevalence of HPV infection in patients suffering from the CRC. Methods: The frequency of the HPV in patients with CRC was studied from 2001 to 2016. To this end, several databases were reviewed, including PubMed, Web of Science, Embase, Cochrane Library, Google Scholar, Iranmedex, and the Scientific Information Database. Then, the analysis was done by Comprehensive Meta-Analysis (V2.0, Biostat) software. Considering heterogeneity between different studies, the random effect model was used and then the results were checked with Cochran’s Q-statistic. Results: The meta-analysis revealed that the frequency of HPV infection in patients with CRC was 33.7% (a 95% CI of 28.4-39.5). The additional stratified analysis also showed that HPV infection in CRC patients was more widespread in European countries compared to Asian and American countries. Conclusion: The high rate of HPV infection is a major concern in sexually transmitted diseases around the world, therefore, controlling high-risk behaviors, vaccination, screening, and HPV subtyping can be useful in managing HPV infections.

The evaluation of HERV-K env, np9, rec, gag expression in normal, polyp and cancerous tissues of gastric and colon

Aim: Gastrointestinal cancer is one of the most alarming cancers worldwide. Infections exert an impact on tumor progression in gastrointestinal tissues. The alteration in the expression of human endogenous retrovirus-K ( HERV-K) genes could remarkably induce oncogenic activity. Materials & methods: In 22 gastric and 23 colon cancer patients, the expression level of HERV-K env, rec, gag and np9 were evaluated. Results: While there was a slight increase in the expression of HERV-K env in colon cancer tissues, the expression level of this gene decreased in gastric tissues. Moreover, the expression of both np9 and gag HERV-K were upregulated only in colon cancer. Nevertheless, rec HERV-K was downregulated in gastric cancer tissues. Conclusion: HERV-K-associated genes can be used as a possible biomarker for cancers diagnosis.

E-cadherin, Snail, ZEB-1, DNMT1, DNMT3A and DNMT3B expression in normal and breast cancer tissues

OBJECTIVE

Breast cancer is known as one of very important cancers among females, given that a variety of external (i.e., environmental risk factors) and internal factors (i.e., genetics, and epigenetics) are related to the emergence and progression of breast cancer. Among genetic and epigenetic factors, DNA methyltransferase and EMT related genes have critical roles in breast cancer pathogenesis. In the study presented here, we investigated expression of DNA methyltransferases (e.g., DNMT1, DNMT3A and DNMT3B) and EMT related genes (e.g., E-cadherin, Snail, ZEB-1).

METHODS AND MATERIALS

Tissue samples were collected from 18 cancer and 24 normal breast tissues. We evaluated the expression levels of DNA methyltransferases and EMT related genes using Quantitative real-time PCR (qRT-PCR).

RESULTS

Our results indicated that the expression levels of ZEB-1, Snail, and DNMT3B were increased in breast cancer subjects in comparison to the control group. On the other hand, there was a significant decrease in E-cadherin expression in breast cancer tissues in comparison to the normal tissues. Moreover, there were no significant changes for DNMT1 and DNMT3A expression in breast cancer tissues when compared to the normal tissues.

CONCLUSION

Taken together, our finding show that up regulation of ZEB-1 and Snail could be associated with down regulation of E-cadherin and results in promotion of cancer cell invasion. Moreover, down regulation of E-cadherin may be related to deterioration of DNMT3B inpatients with breast cancer.

Evaluating the expression level of HERV-K env, np9, rec and gag in breast tissue

OBJECTIVE

Breast cancer is one of the most common health problems. It has been suggested that several risk factors, either considered as external or internal, play a critical role in the pathogenesis of breast cancer, which among them, HERV-k, has the most fundamental role. In the present study, we aimed to evaluate the role of HERV-k env, gag, rec, np9 expressions in breast cancer progression.

MATERIALS AND METHODS

We collected 40 breast cancer tissues and their normal adjacent ones. After extracting the RNA of breast samples, we evaluated the expression of HERV-k env, gag, rec, np9 by using Quantitative real-time PCR (qRT-PCR).

RESULTS

The resulting data revealed that while there was a meaningful increase in the expression level of HERV-k env, gag and np9 in breast cancer tissues (P ≤ 0.01, 0.05, 0.05, respectively), we failed to find any significant elevation in the expression level of rec mRNA level.

CONCLUSION

The results of our study suggested that there is a plausible correlation between the mRNA expression level of HERV-K env, gag and np9 and the progression of breast cancer, proposing these markers as promising biomarkers to diagnose breast cancer.

Evaluation of microRNA-9 and -192 expression levels as biomarkers in patients suffering from breast cancer

Given the global outbreak of breast cancer and its debilitating effect on women's health, it is not surprising that tremendous efforts have been made with an aim of shedding more light on the mechanisms involved in the pathogenesis of this type of cancer. Among the long list of risk factors associated with this malignancy, recently, the role of microRNAs (miRNAs or miRs) has turned into a hotspot for breast cancer investigations. miRNAs approximately 20 nucleotides in length and are located in either an exon or an intron, playing a role in the regulation of gene expression. In the present study, we extracted RNA from both the serum and cancerous tissue of breast cancer patients and after synthesizing the cDNA, we performed quantitative PCR to determine the expression levels of miR-9 and miR-192. The resulting data revealed that while the mRNA expression level of miR-9 was significantly decreased in the breast cancer tissues, there was no noticeable change in the expression level of this miRNA in the serum samples. Likewise, we found that the marked downregulation of miR-192 was only restricted to the cancerous tissues, but was not found in the serum of patients. Based on the meaningful downregulation of the expression of miR-9 and miR-192, this study provides a plausible framework for these miRNAs as effective biomarkers for breast cancer patients.

Histone deacetylases in virus-associated cancers

Oncogenic viruses are one of the most important causes of cancer worldwide. The pathogens contribute to the establishment of human malignancies by affecting various cellular events. Epigenetic mechanisms, such as histone modification methylation/demethylation, are one of the most critical events manipulated by oncogenic viruses to drive tumorigenesis. Histone modifications are mediated by histone acetylation and deacetylation, regulated by histone acetyltransferases (HATs) and histone deacetylases (HDACs), respectively. Dysregulation of HDACs activity affects viral tumorigenesis in several ways, such as manipulating tumor suppressor and viral gene expression. The present review aims to describe the vital interactions between both cancer-caused/associated viruses and the HDAC machinery, particularly by focusing on those viruses involved in gastrointestinal tumors, as some of the most common viral-mediated cancers.

Serum and tissue miRNAs: potential biomarkers for the diagnosis of cervical cancer

Background

Finding new biomarkers for the early detection of cervical cancer is an essential requirement in this field. In this study, we aimed to evaluate the expression level of potential biomarkers in progression of cervical cancer in patients with cervical cancer compared to normal subjects.

Methods

The expression levels of tissue and serum miRNAs, including miR-9, miR-192 and miR-205, were investigated in 36 normal, 18 precancer, and 18 cervical cancer samples using real-time polymerase chain reaction.

Results

The results showed the higher significant expressions of miR-9, miR-192 and miR-205 in the tissue of cancer samples than those in the normal samples. Moreover, the miR-192 and miR-205 expression were significantly increased in the cancer group in comparison with the precancer group. Examination of serum samples revealed the increase in the expression level in the cancer groups than in the normal samples, for miR-9, miR-192 and miR-205 and the expressions of miR-9, miR-192 and miR-205 were significantly up-regulated in the precancer group in comparison with the normal group. Also the expression of miR-205 was remarkably increased in the cancer group in comparison with the precancer group. The receiver operating characteristic (ROC) analyses showed the highest area under the curve value for miR-192.

Conclusions

Given the increased expression level of miR-192 in cancer and in precancerous tissue and serum compared with the normal tissue and serum validated by analysing the ROC curve, miR-192 can be used as potential biomarker for the early detection of cervical cancer.

Exploiting yoeB-yefM toxin-antitoxin system of Streptococcus pneumoniae on the selective killing of miR-21 overexpressing breast cancer cell line (MCF-7)

Toxin-antitoxin (TA) systems are two-component genetic modules widespread in bacterial and archaeal genomes, in which the toxin module is rendered inactive under resting conditions by its antitoxin counterpart. Under stress conditions, however, the antitoxin is degraded, freeing the toxin to exert its lethal effects. Although not evolved to function in eukaryotes, some studies have established the lethal activity of these bacterial toxins by inducing apoptosis in mammalian cells, an effect that can be neutralized by its cognate antitoxin. Inspired by the way the toxin can become active in eukaryotes cells, we produced an engrained yoeB-yefM TA system to selectively kill human breast cancer cells expressing a high level of miR-21. Accordingly, we generated an engineered yefM antitoxin gene with eight miR-21 target sites placed in its 3'untranslated region. The resulting TA system acts autonomously in human cells, distinguishing those that overexpress miR-21, killed by YoeB, from those that do not, remaining protected by YefM. Thus, we indicated that microRNA-control of the antitoxin protein of bacterial TA systems constitutes a novel strategy to enhance the selective killing of human cancer cells by the toxin module. The present study provides significant insights for developing novel anticancer strategies avoiding off-target effects, a challenge that has been pursued by many investigators over the years.

Aneuploidy and oncoviruses

Seven oncogenic viruses are known for tumorigenesis and contribute to 12% of all human cancers. The oncogenic factors, the target tissue, and pathology of cancer vary among these viruses with several mechanisms proposed for the initiation and development of cancer. Aneuploidy in cells is associated with anomalies in chromosome number that can be a hallmark of cancer, a disease defined by expanded proliferative potential. In this review, we summarize the different mechanisms of aneuploidy and furthermore discuss recent findings of the role of viral oncoproteins in inducing cellular aneuploidy that might facilitate tumorigenesis. Improved understanding of viral oncogenesis may help to find new strategies for controlling virus-associated cancers.

Transcriptional Regulation of Epithelial to Mesenchymal Transition Related Genes by Lipopolysaccharide in Human Cervical Cancer Cell Line HeLa

Objective:

Cancer is one of the common diseases in the world, and cervical cancer is the fourth one. In this type of cancer, many risk factors, especially infectious diseases, such as human papilloma virus (HPV) and gram-negative bacteria can have important effects on the expression of epithelial to mesenchymal transition related genes like Snail,E-cadherin, and ZEB-1, responsible for connecting cell tissues. In this study, we have investigated the effect of Escherichia coli O111:B4 Lipopolysaccharide (LPS) on HPV positive cell line (HeLa), the expression level of the (Snail, E-cadherin, and ZEB-1), HPV oncogenes (E6, E7) and also microRNA-9, 192.

Materials and Methods:

HeLa cell line was treated with LPS to analyze Snail, E-cadherin, ZEB-1, E6, E7 and also microRNA-9, 192 expression by quantitative real-time PCR in 24, 48 and 72 hours.

Results:

Quantitative real-time PCR revealed a significant reduction in E-cadherin mRNA level at 10ug/L of LPS in three time-points and after 24 hours at 5ug/L of LPS; however, ZEB-1 at 10ug/L of LPS and Snail at 5, 10ug/L of LPS are up-regulated. E7 also illustrated a slight increase, but we did not find any relationship between E7 and LPS treatment. Additionally, there are upward trends in microRNA-9, 192 levels.

Conclusion:

The result of this study, LPS is able to reduce E-cadherin expression, caused by increase in repressor E-cadherin protein expression and some microRNAs, probably. Since bacterial infection can be in cervical site, it is likely to be effective in reducing the E-cadherin expression in the EMT and enhance cancer process, therefore; removing these infections by using the appropriate antibiotics may result in slowing down this process, which requires more research.

Molecular characterization of the glycoprotein and fusion protein in human respiratory syncytial virus subgroup A: Emergence of ON-1 genotype in Iran

HRSV is a principle cause of infant hospitalization, childhood wheezing and a common pathogen in the elderly. Limited information exists regarding HRSV genotypes in Iran. In order to better understand HRSV strain diversity, we performed an in-depth evaluation of the genetic variability of the HRSV F protein detected in children under two years of age that, presented with acute respiratory symptoms during 2015-2016 in Tehran. A total of 180 nasopharyngeal swabs were evaluated. The HRSV positive samples were genotyped for G and F gene sequences using RT-PCR and sequencing methods. Phylogenetic analysis was performed using the neighbor-joining and maximum likelihood methods. Genetic and antigenic characteristics of the F gene, nucleotide and amino acids in significant positions and immune system binding regions, as well as the p-distance, positive/negative selection site, linear epitopes and glycosylation sites were investigated in all selected sequences. Among the 83 HRSV positive samples, the Fifty-five cases were successfully sequenced. All of them were classified as subgroup A and belonged to the ON-1 genotype, which possessed 72-nt duplication in the G gene. This study is the first report on the emergence of ON-1 in Iran. ON-1 Iranian sequences clustered in three lineages according to virus fusion (F) gene variations. F gene sequence analysis showed that all genetic changes in the isolates from Iran were base substitutions and no deletion/insertions were identified. The low dN/dS ratio and lack of positively selected sites showed that the fusion genes found in the strains from Iran are not under host selective pressure. Continuing and long-term molecular epidemiological surveys for early detection of circulating and newly emerging genotypes are necessary to gain a better understanding of their epidemic potential.

DNA methyltransferases in virus-associated cancers

Human tumor viruses are either casually linked or contribute in the development of human cancers. Viruses can stimulate oncogenesis through affecting diverse biological pathways in human cells. Growing data have demonstrated frequent involvement of one of the most characteristic parts of cellular epigenetic machinery, DNA methylation, in the oncogenesis. DNA methylation of cellular genes is catalyzed by DNA methyltransferases (DNMTs) as a key effector enzyme in this process. Dysregulation of DNMTs can cause aberrant gene methylation in promoter of cancer-related genes including tumor suppressor genes, resulting in gene silencing. In this regard, the role of tumor viruses is remarkable. Here, in this review, we used published information to elucidate whether tumor viruses are able to manipulate DNMT regulation, and if so, what are its consequences in the process of oncogenesis. This essay also aims to shed light on which cellular pathways have been engaged by viruses to induce DNMTs.

The roles of FOX proteins in virus-associated cancers

Forkhead box (FOX) proteins play a crucial role in regulating the expression of genes involved in multiple biological processes, such as metabolism, development, differentiation, proliferation, apoptosis, migration, invasion, and longevity. Deregulation of FOX proteins is commonly associated with cancer initiation, progression, and chemotherapeutic drug resistance in many human tumors. FOX proteins deregulate through genetic events and the perturbation of posttranslational modification. The purpose of the present review is to describe the deregulation of FOX proteins by oncoviruses. Oncoviruses utilize various mechanisms to deregulate FOX proteins, including alterations in posttranslational modifications, cellular localization independently of posttranslational modifications, virus-encoded miRNAs, activation or suppression of a series of cell signaling pathways. This deregulation can affect proliferation, metastasis, chemotherapy resistance, and immunosuppression in virus-induced cancers and help to chronic viral infection, development of gluconeogenic responses, and inflammation. Since the PI3K/Akt/mTOR signaling pathway is the upstream FOXO, suppressing it can cause FOXO function to return, and this can be one of the reasons for patients to recover from the infection of the viruses used to treat these inhibitors. Hence, FOX proteins could serve as prognosis markers and target therapy specifically in cancers caused by oncoviruses.

The Role of MicroRNA Signature as Diagnostic Biomarkers in Different Clinical Stages of Colorectal Cancer

OBJECTIVES

Colorectal cancer (CRC) is one of the most common cancers and a major cause of cancer-related death worldwide. The early diagnosis of colorectal tumors is one of the most important challenges in cancer management. MicroRNAs (miRNAs) have provided new insight into CRC development and have been suggested as reliable and stable biomarkers for diagnosis and prognosis. This study's objective was to analyze the differential expression of miRNAs at differentstages of CRC searching for possible correlation with clinicopathological features to examine their potential value as diagnostic biomarkers.

MATERIALS AND METHODS

In this case-control study, plasma and matched tissue samples were collected from 74 CRC patients at stage II-IV as well as blood samples from 32 healthy controls. After exhaustive study of the current literature, eight miRNAs including miR-200c, 20a, 21, 31,135b, 133b,145 and let-7g were selected. The expression level of the miRNAs was assayed by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). Statistical analysis, including t test , Mann-Whitney U, Kruskall-Wallis tests and receiver operating characteristic (ROC) curve was applied, where needed.

RESULTS

Significantly elevated levels of miR-21, miR-31, miR-20a, miR-135b, and decreased levels of miR- 200c, miR-145 and let-7 g were detected in both plasma and matched tissue samples compared to the healthy group (P<0.05). However, no significant differences were observed in the expression level of plasma and tissue miR-133b (P>0.05). ROC for tissue miRNAs showed an area under the ROC curve (AUC) of 0.98 and P<0.001 for miR-21, 0.91 and P<0.001 for miR-135b, 0.91 and P<0.001 for miR-31, and 0.92 and P<0.001 for miR-20a.

CONCLUSIONS

Our results indicate that the expression levels of microRNAs are systematically altered in CRC tissue and plasma. In conclusion, detection of miR-21, miR-135b, miR-31 and miR-20a levels in the tissue might be helpful to illuminate the molecular mechanisms underlying CRC carcinogenesis and serve as tumor-associated biomarkers for diagnosis.

Viruses as key modulators of the TGF-β pathway; a double-edged sword involved in cancer

Transforming growth factor-β (TGF-β) signaling pathway is a key network in cell signaling that controls vital processes such as proliferation, differentiation, apoptosis, epithelial-mesenchymal transition, and migration, thus acting as a double-edged sword in normal development and diseases, in particular organ fibrosis, vascular disorders, and cancer. Early in tumorigenesis, the pathway exerts anti-tumor effects through suppressing cell cycle and inducing apoptosis, while during late stages, it functions as a tumor promoter by enhancing tumor invasiveness and metastasis. This signaling pathway can be perturbed by environmental and genetic factors such as microbial interference and mutation, respectively. In this way, the present review describes the modulation of the TGF-β pathway by oncogenic human viral pathogens and other viruses. The main mechanisms by which viruses interferes with TGF-β signaling seems to be through (1) the alteration of either TGF-β protein expression or activation, (2) the modulation of the TGF-β receptors or SMADs factors (by interfering with their levels and functions), (3) the alteration of none-SMAD pathways, and (4) indirect interaction with the pathway by the modulation of transcriptional co-activator/repressor and regulators of the pathway. Given the axial role of this pathway in tumorigenesis, it can be regarded as an attractive target for cancer therapy. Hence, further investigations on this subject may represent molecular targets among either TGF-β signaling molecules or viral factors for the treatment and management of viral infection consequences such as cancer.

Prevalence of human respiratory syncytial virus in Iran: a systematic review and meta-analysis

Aim: We sought to determine the prevalence of human respiratory syncytial virus (HRSV) in people in Iran between the year 1996 and 2016. Methods: Prevalence of HRSV in Iran was determined from 1996 to 2016 using data from PubMed, Web of Science, EMBASE, Cochrane Library, Google Scholar and Iranian databases. Analysis was performed by Comprehensive Meta-Analysis software. Result: The prevalence of HRSV infections was 18.0% (95% CI: 14.6–22.0) in people in different regions of Iran. Additionally, the incidence of HRSV in north, center, west and south of Iran were 16.4% (95% CI: 11.8–22.4), 20.0% (95% CI: 15.5–25.5), 16.8% (95% CI: 10.0–27.0) and 10.6% (95% CI: 2.4–36.9), respectively. Conclusion: According to the high prevalence of HRSV infection among people with respiratory infections in Iran, HRSV screening and evaluating of co-circulate HRSV genotypes can be helpful for vaccination design in the future.

Role of viruses in gastrointestinal cancer

Gastrointestinal cancers are a global public health problem, which represent a vast majority of all cancer-caused deaths in both men and women. On the other hand, viral pathogens have been long implicated as etiological factors in the onset of certain human cancers, including gastrointestinal tumors. In this regard, Human Papilloma Virus (HPV), Epstein-Barr Virus (EBV), and John Cunningham Virus (JCV) have been more strongly suggested to be involved in gastrointestinal carcinogenesis; so that, the association of HPV with oropharyngeal and anal cancers and also the association of EBV with gastric cancer have been etiologically confirmed by epidemiological and experimental investigations. Although, the association of other viruses is less evident, but may rely on co-factors for their oncogenic roles. Therefore, to improve the prevention and treatment of these classes of cancer, their association with viral agents as potential risk factors should be investigated with care. In this respect, the present review has focused on the existing literature on the subject of viral involvement in gastrointestinal tumorgenesis, by covering and discussing various gastrointestinal cancers, corresponding viral agents and their oncogenic aspects and then summarizing evidences either supporting or rejecting a causal role of these pathogens in gastrointestinal malignancies.

Relationship of human herpes virus 6 and multiple sclerosis: A systematic review and meta-analysis

Infection with human herpes viruses has been suggested to contribute to multiple sclerosis (MS), while interaction between human herpes 6 (HHV6) and MS remain unclear yet. Here, we conducted a meta-analysis on the relationship of HHV6 infection and MS. All related studies were collected from major databases. The analyses were performed by STATA 14 and Comprehensive Meta-Analysis V2.0 softwares. Pooled odds ratios (ORs) and 95%CIs were calculated from the raw data of the including studies by the random effects models when I2 > 50% and fix model when I2 < 50%. Thirty nine studies were included in the meta-analysis that 34 studies used molecular assays and 7 studies used serological assays for diagnosis of HHV6 infected cases. The relationship of HHV6 and MS was significant in healthy control group by yielding a summary OR of (2.23 [1.5-3.3], p = 0.06). A significant HHV6 association with MS were in the studies with >6 score that used serum/blood sample with OR of (6.7 [95%CI 4.8-8.6], p < 0.00001) and in serological studies, IgM positive titer in other neurological diseases (OND) control group was significant with OR of (8.3 [95%CI 3-24.07], p < 0.00001). This study has been showed that there were significant relationship between MS and HHV6 infection.