Correspondence Re: Ghosh A and Heston WDW. Tumor target prostate specific membrane antigen (PSMA) and its regulation in prostate cancer. J Cell Biochem 91:528-539, 2004

Does lymph node localization affect prostate-specific membrane antigen uptake?

OBJECTIVE

To investigate the relationship between lymph node (LN) size and localization and prostate-specific membrane antigen (PSMA) uptake in patients with prostate cancer.

PATIENTS AND METHODS

Between February 2015 and February 2017, a total of 178 patients diagnosed with prostate adenocarcinoma by gallium-68 PSMA PET/computed tomography were evaluated. Seventy-eight patients with LN PSMA uptake were included in the study.The short-axis diameter and maximum and mean standardized uptake values (SUV) were measured from axial images of LNs with PSMA uptake. LN conglomerates were considered a single lesion. Patients were divided into two groups according to the presence (group 1) or absence (group 2) of bone uptake in addition to the LN uptake; subgroups were constituted according to the short-axis diameter and PSMA-positive LN region for each group. LNs were classified according to their localization as pelvic, abdominal, or cervical/thoracic.

RESULTS

In both groups, the SUV were significantly higher in LNs with short-axis diameters more than 8 mm than those with diameters up to 8 mm (P < 0.001 and < 0.001, respectively). Also, both groups showed a moderate correlation between the LN size and SUV.When the analysis was carried out according to the localization, but after excluding the LN conglomerates, the correlation between the pelvic and abdominal LNs was higher in the second group.

CONCLUSION

The highest significant positive correlation between LN size and SUV was in patients with pelvic and abdominal LN metastases without bone involvement according to the gallium-68 PSMA PET/computed tomography images in our study.

Recent advances of bispecific antibodies in solid tumors

Cancer immunotherapy is the most exciting advancement in cancer therapy. Similar to immune checkpoint blockade and chimeric antigen receptor T cell (CAR-T), bispecific antibody (BsAb) is attracting more and more attention as a novel strategy of antitumor immunotherapy. BsAb not only offers an effective linkage between therapeutics (e.g., immune effector cells, radionuclides) and targets (e.g., tumor cells) but also simultaneously blocks two different oncogenic mediators. In recent decades, a variety of BsAb formats have been generated. According to the structure of Fc domain, BsAb can be classified into two types: IgG-like format and Fc-free format. Among these formats, bispecific T cell engagers (BiTEs) and triomabs are commonly investigated. BsAb has achieved an exciting breakthrough in hematological malignancies and promising outcome in solid tumor as showed in various clinical trials. In this review, we focus on the preclinical experiments and clinical studies of epithelial cell adhesion molecule (EpCAM), human epidermal growth factor receptor (HER) family, carcinoembryonic antigen (CEA), and prostate-specific membrane antigen (PSMA) related BsAbs in solid tumors, as well as discuss the challenges and corresponding approaches in clinical application.

Prostate--specific G protein couple receptor genes and STAG1/PMEPA1 in peripheral blood from patients with prostatic cancer

We investigated whether prostate - specific G protein couple receptor genes and STAG1/PMEPA1 gene expression in peripheral- blood could be useful as a diagnostic or prognostic marker of prostate cancer. Circulating cells were identified by reverse transcription-polymerase chain reaction (RT-PCR) to detect PSGR and STAG1/PMEPA1 mRNA in peripheral blood (PB) from 11 patients with treated prostate cancer (CaP), 11 with newly-diagnosed untreated CaP and 20 with benign prostatic hyperplasia (BPH) (controls). RT-PCR amplified PSGR in 8 of 11 untreated and in 9 of 11 treated patients with CaP and in 16 of 20 with BPH; whereas it amplified PMEPA1 in 1 of 11 untreated and in 7 of 11 treated patients with CaP and in 4 of 20 with BPH. In our control tissues and cell lines nearly all the prostatic and non- prostatic tissues and cell lines expressed PSGR mRNA, whereas only one prostatic neoplastic tissue and the androgen-responsive (LNCaP) and androgen non-responsive (PC3) prostatic cell lines expressed PMEPA1. These findings suggest that the investigated genes are poorly specific and probably of little use as diagnostic or prognostic markers in peripheral blood for monitoring prostate cancer progression and recurrence.

Can p503s, p504s and p510s gene expression in peripheral-blood be useful as a marker of prostatic cancer?

BACKGROUND

The aim of the study was to investigate whether p503S, p504S and p510S gene expression in peripheral-blood be useful as a diagnostic or prognostic marker of prostatic cancer.

METHODS

Circulating cells were identified by reverse transcription-polymerase chain reaction (RT-PCR) to detect p503S, p504S and p510S mRNA in peripheral blood (PB) from 11 patients with treated prostatic carcinoma (CaP), 11 with newly-diagnosed untreated CaP and 20 with benign prostatic hyperplasia (BPH) (controls).

RESULTS

RT-PCR amplified P503S in 7 of 11 untreated and 2 of 11 treated patients with CaP and 5 of 20 with BPH; p504S in 7 of 11 untreated and in 9 of 11 treated patients with CaP and 11 of 20 with BPH; whereas it amplified p510S in all subjects with CaP and in 15 of 20 with BPH.

CONCLUSION

These findings suggest that the investigated genes are poorly specific and probably of little use as diagnostic or prognostic prostatic markers in peripheral blood for monitoring disease progression and recurrence.