Association of hyaluronic acid family members (HAS1, HAS2, and HYAL-1) with bladder cancer diagnosis and prognosis

Abstract

Background: Cancer biomarkers are the backbone for the implementation of individualized approaches to bladder cancer (BCa). Hyaluronic acid (HA) and all 7 members of the HA family, that is, HA synthases (HA1, HA2, HA3), HYAL-1 hyaluronidase, and HA receptors (CD44s, CD44v, and RHAMM), function in tumor growth and progression. However, the diagnostic and prognostic potential of these 7 HA family members has not been compared simultaneously in any cancer. We evaluated the diagnostic and prognostic potential of HA family members in BCa.

Methods: Using quantitative PCR and immunohistochemistry, expression of HA family members was evaluated in prospectively collected bladder tissues (n = 72); mean and median follow-up were 29.6 ± 5.3 and 24 months, respectively. Transcript levels were also measured in exfoliated urothelial cells from urine specimens (n = 148).

Results: Among the HA family members, transcript levels of the HA synthases, HYAL-1, CD44v, and RHAMM were 4- to 16-fold higher in BCa tissues than in normal tissues (P < .0001); however, CD44s levels were lower. In univariate and multivariate analyses, tumor stage (P = .003), lymph node invasion (P = .033), HYAL-1 (P = .019), and HAS1 (P = .027) transcript levels, and HYAL-1 staining (P = .021) were independently associated with metastasis. Tumor stage (P = .019) and HYAL-1 (P = .046) transcript levels were also associated with disease-specific mortality. Although HA synthase and HYAL-1 transcript levels were elevated in exfoliated urothelial cells from BCa patients, the combined HAS2-HYAL-1 expression detected BCa with an overall sensitivity of 85.4% and a specificity of 79.5% and predicted BCa recurrence within 6 months (P = .004; RR = 6.7).

Conclusions: HYAL-1 and HAS1 expression predicted BCa metastasis, and HYAL-1 expression also predicted disease-specific survival. Furthermore, the combined HAS2-HYAL-1 biomarker detected BCa and significantly predicted its recurrence.

Figure 1. Scatter diagrams of HA-synthase and HYAL-1 mRNA levels in bladder tissues

mRNA levels of each of the seven HA-family molecules in bladder specimen are shown. The mean ± SD scores for each biomarker are indicated. NBL: normal bladder; NBL-O: NBL tissue obtained from organ donors; NBL-B: NBL tissue obtained from BCa patients at the time of cystectomy. LG: low-grade BCa; HG: high-grade BCa.

Figure 2. Analyses of HA-synthase(s) and HYAL-1 expression in bladder tissues

A: HA, HAS1, HAS2, HAS3 and HYAL-1 were localized in normal bladder, low-grade (LG) and high-grade (HG) BCa tissues by IHC. Representative specimens from each category are shown. B: Scatter diagrams of staining scores of HA, HAS1, HAS2, HAS3 and HYAL-1 in bladder specimens are shown. Five NBL specimens could not be stained due to poor fixation resulting in the loss of tissue from the slides during staining.

Figure 2. Analyses of HA-synthase(s) and HYAL-1 expression in bladder tissues

A: HA, HAS1, HAS2, HAS3 and HYAL-1 were localized in normal bladder, low-grade (LG) and high-grade (HG) BCa tissues by IHC. Representative specimens from each category are shown. B: Scatter diagrams of staining scores of HA, HAS1, HAS2, HAS3 and HYAL-1 in bladder specimens are shown. Five NBL specimens could not be stained due to poor fixation resulting in the loss of tissue from the slides during staining.

Figure 3. Scatter diagrams of HA-synthase and HYAL-1 mRNA levels in exfoliated cells

The distribution of the mRNA levels of each of the seven HA-family members among the study cohort is shown. The mean ± SD scores for each biomarker are indicated.