Successful treatment of a high-risk nonseminomatous germ cell tumor using etoposide, methotrexate, actinomycin D, cyclophosphamide, and vincristine: A case report

Structural and Functional Insights into Targeting GCCG Sites in the EGFR Promoter by Two DNA Intercalators to Inhibit Breast Cancer Metastasis

Chemotherapeutic drugs are commonly used to treat cancers lacking targeted therapy options. However, their low specificity limits their treatment effectiveness. We report here that the cooperative binding of doxorubicin (Dox) with actinomycin D (ActD) enhances the specificity for consecutive GCCG sites in DNA. Using X-ray crystallography, we determined the crystal structure of ActD and Dox bound to d(AGCCGT)2 DNA. ActD intercalation at the GpC site induces a novel Dox binding mode at the adjacent CpG step. This ensures a snug fit, avoids steric clashes, and enhances the specificity. Transcriptome analysis revealed that combining Dox with ActD synergistically down-regulates EGFR in TNBC cells. Additionally, it reduces EGFR promoter activity. In vivo, the combination significantly suppresses tumor growth and outperforms the standard Dox and cyclophosphamide regimen in inhibiting metastasis. This study highlights targeting the activated EGFR pathway with sequence-specific DNA-targeting drug combinations as a potential TNBC treatment.

The tumor or inflammation? a case report on primary pulmonary choriocarcinoma

Choriocarcinoma is a rare malignant germ cell neoplasm with high invasiveness, the majority of which are pregnancy-related, and the female genital tract is the most prevalent site of the disease. Although early-stage choriocarcinoma typically metastasizes to the lungs, primary pulmonary choriocarcinoma is extremely rare. Primary pulmonary choriocarcinoma is difficult to diagnose, and it progresses rapidly. Combined with the difficulty of treatment, the prognosis of patients is generally poor. In this article, we retrospectively analyzed a case of female primary pulmonary choriocarcinoma, combined with a review of literature, to understand and describe the diagnostic and treatment progress of PPC.

Staggered intercalation of DNA duplexes with base-pair modulation by two distinct drug molecules induces asymmetric backbone twisting and structure polymorphism

The use of multiple drugs simultaneously targeting DNA is a promising strategy in cancer therapy for potentially overcoming single drug resistance. In support of this concept, we report that a combination of actinomycin D (ActD) and echinomycin (Echi), can interact in novel ways with native and mismatched DNA sequences, distinct from the structural effects produced by either drug alone. Changes in the former with GpC and CpG steps separated by a A:G or G:A mismatch or in a native DNA with canonical G:C and C:G base pairs, result in significant asymmetric backbone twists through staggered intercalation and base pair modulations. A wobble or Watson–Crick base pair at the two drug-binding interfaces can result in a single-stranded ‘chair-shaped’ DNA duplex with a straight helical axis. However, a novel sugar-edged hydrogen bonding geometry in the G:A mismatch leads to a ‘curved-shaped’ duplex. Two non-canonical G:C Hoogsteen base pairings produce a sharply kinked duplex in different forms and a four-way junction-like superstructure, respectively. Therefore, single base pair modulations on the two drug-binding interfaces could significantly affect global DNA structure. These structures thus provide a rationale for atypical DNA recognition via multiple DNA intercalators and a structural basis for the drugs’ potential synergetic use.