C. trachomatis infection activates latent HHV-6, and HHV-6 in turn promotes persistence of C. trachomatis. Both have been reported in cases of ovarian cancer, leaving the authors to wonder if a co-infection might increase the risk for developing ovarian cancer.
HHV-6 latency gene U94 has anti-cancer effects in triple-negative breast cancer cells
The U94 “latency” gene of HHV-6, interferes with breast cancer proliferation and potentiates chemotherapy.
HHV-6 DR7 found to promote glioma development and progression
A Chinese group found HHV-6 direct repeat 7 in 48% of glioma tumors. Furthermore, they determined that DR7 overexpression could promote glioma cell migration, invasion and angiogenesis. Expression profiles showed that DR7 created an inflammatory microenvironment that enhanced degradation of the extracellular matrix.
HHV-6 in Cancer: Does it play a role?
Since its discovery, HHV-6 has been studied in the context of lymphoproliferative disorders and various types of cancer. Several obstacles, particularly the ubiquitous nature of the virus, have made it difficult to determine exactly how HHV-6 might, or might not, be involved in tumor development.
Cancer related fatigue and HHV-6 & HHV-7 saliva DNA levels
Investigators from Japan looked at HHV-6 and HHV-7 DNA levels in saliva to see if they might be biomarkers for cancer-related fatigue (CRF) in multiple myeloma patients.
HHV-6+ lymph nodes can lead to a faulty cancer diagnosis
Investigators at the National Cancer Institute found that HHV-6+ lymph nodes can be identified in biopsies from both lymphadenopathy and malignancies. They warn that failing to identify HHV-6 in these biopsies can lead to misdiagnosis in lymphoma cases.
HHV-6A IE1 antibodies associated with increased risk of non-Hodgkin lymphoma
Using a novel serological assay that can differentiate HHV-6A from HHV-6B, investigators found HHV-6A immediate early antibodies to be associated with an increased risk of non-Hodgkin lymphoma.
Cross-sectional analysis of CD8 T cell immunity to HHV-6B identifies new targets for adoptive T cell therapy
German investigators conducted a broad scale analysis of CD8 T cell responses to HHV-6B, identifying novel epitopes with potential for immunotherapy or vaccines. The strongest responses were directed against an epitope from IE-2.
HHV-6 and lymphoproliferative syndromes: a review
The authors discuss how HHV-6 may contribute to the progression of reactive lymphoproliferative disorders by spurring a dysfunctional immune response.
HHV-6A sequences found in ovarian cancer tissues but not in controls
A broadscale investigation of the ovarian cancer oncobiome using a microarray system PathoChip found HHV-6A sequences at or near genes associated with tumorigenesis in ovarian cancer tissue samples.
Deep sequencing analysis finds HHV-6, CMV and EBV in a subset of stomach and colon cancers
A team at University of Pittsburgh analyzed a large database of deep sequencing data from tumor and control tissues to look for viral sequences in 22 different cancers. They were surprised to find several herpesviruses in gastrointestinal cancers but not in control tissues.
Inherited ciHHV-6 increases risk of developing acute GVHD and CMV in transplant patients
A higher prevalence of inherited virus was found in patients
Investigators at Fred Hutchinson Cancer Center determined that transplant patients with inherited ciHHV-6 were twice as likely to develop acute graft vs host disease and three times more likely to develop high level CMV viremia. Transplant patients were also significantly more likely to have inherited ciHHV-6 than donors.
Could HHV-6 U94 attenuate tumor cell growth and metastasis?
Italian investigators found that HHV-6 latency-associated gene U94, inserted in a HSV1 vector, inhibited the development of breast cancer, cervical cancer, and lung metastasis. It also impaired tumor driven angiogenesis.
Neoplasia: could iciHHV-6A cause a benign HPV strain to turn deadly?
Human papillomavirus 4 is a benign strain not associated with cancer. However, in a woman with inherited chromosomally integrated HHV-6A, a high grade vaginal squamous lesion developed rapidly. The authors warn that there may be a synergistic effect between HPV4 and iciHHV6A.
Does the high level of U94 in iciHHV-6 contribute to abnormal ‘marker’ chromosomes and cancer?
Investigators from the University of Ferrara, Italy have found evidence suggesting that high levels of U94 in ciHHV6 may predispose to the formation of marker chromosomes. A patient with diffuse large B-cell lymphoma positive for inherited chromosomally integrated HHV-6A and HHV-6A was also found in a marker chromosome, an abnormal piece of chromosome that is seen in some leukemia and lymphomas.